1. CONSCIOUSNESS AND SELF-CONSCIOUSNESS

Consciousness is the focal point of epistemology. The Cartesian "cogito ergo sum" defines the problem of self-consciousness but not that of our position in the universe, nor the relation of the universe with us. If we try to extend the purport of Cartesian consciousness to the universe as-we-know-it, the only solid starting point is our experience. In so doing it is relevant to keep in mind that the evolution of our brain is the consequence of its adaptation to the evolving environment of planet Earth, necessarily depending upon the Euclidean frame of reference into which the fittest characters were selected for survival. Our brain is well equipped to know where are the right and the left arms, to move quickly the rest of the body in its fourth dimension and, since the appearance of gene mutations that triggered the development of the human cortex (Evans et al. 2005; Mekel-Bobrov et al. 2005), it has also learnt how to answer to problems non solvable in Euclidean terms by developing abstract thought, symbolism, metaphysics. Briefly, self-consciousness is in humans a phenotype determined by, and interacting with, the genotype that encodes it, fruit of local evolution. Is the purport of consciousness extendable beyond nervous systems? And: can the Observer's principle, the cage that apparently compresses all the logic efforts in this quest for a wider horizon, be violated?

2. RHIZOME

Going back in time, each human being is genetically connected with all the other human beings and (there is no need to argue too much on this point) with the rest of living organisms. With the help of symbolic thought, the image that best describes this concept is that of a rhizome, stressing the unity of the living and the ensemble of its general connections. This concept was introduced by Deleuze and Guattari in A Thousand Plateaus (1980). In their original wording the rhizome follows the principles:

In the sense of this metaphor, the living world is a totally connected network in which each single organism is a momentary embodiment of a specific genotype that starts its life (simplifying a little) in the moment of the replication and/or of the recombination (according to the system) of its parental genetic materials, and ends in the moment of the dissolution of its own genome. Each genotype is on-line connected with the genotypes from which it derives and with those that could derive from it. The living network is a unit in the time- and genetic-space extending back to the possibly multi-rooted Last Universal Common Ancestor(s). Before that, individuals were by definition not existing as such, entities immersed in the swamp of combinatorial biochemistry. Briefly, one needs to critically examine the very concept of life.

3. DEFINITION OF LIFE

The accepted definition "life is a self-sustained chemical system capable of undergoing Darwinian evolution" (Joyce, 1994) is rigorous and rigid at the same time. I may recognize myself as being well described and represented by this definition, as could any giraffe or alga or bacterium or even virus I can think of in a Linnaean world. But: a) life is a process and not a system; b) evolution may not be necessarily needed in a omni-comprehensive definition of life. One could imagine an environment in which there are no variations; or in which variations are cyclic and highfrequency, occurring in a time scale that does not commensurably correspond to the time scale of the living entities it harbors and supports. In such environments evolution would not be a categorical property.

Before LUCA, cycles had to establish themselves that could provide the necessary organization of matter, energy control and directional flow of chemical information. Untangling of these biochemical and biophysical hanks has proven difficult and the scenarios in which prebiotic processes are sketched are still biased between metabolism-first, genetic-first or, even, membranesfirst. The three "Firsts" should have possibly been three acts of the same comedy, played together on the same stage. The organization of a living (defined and reproducible) entity is difficult if the same Darwinian "warm little pond" (Darwin, 1888) did not allow the simultaneous formation of ins-and-outs by lipid-based membranes, the organization of metabolic cycles as the reductive citric acid cycle (Morowitz, 1970), which is reasonably indicated as the key to ur-metabolism, and a way to store and accurately transmit the necessary coded information. For any sensible and comprehensive theory of life an initial unitary chemical frame from which the three Firsts took place together, or in a parallel and interactive manner, is badly needed.

A compelling example of the proficiency of these interactions was provided (Mansy et al. 2008), showing the promoting effect exerted by nucleic acids on vesicle division. Briefly, life extends beyond the limits of the individual, its lower border being historically indefinable. Nevertheless, a bottom-down approach might indicate the key principles on which it is based.

4. THE STANDARD PRINCIPLES FOR LIFE: 1) CONTINUITY

In terms of physics, the text-book notion underpinning life is a momentary slack of the rush toward entropy, as dictated by the second principle of thermodynamics. In terms of chemistry, life is the concerted unidirectional transfer of chemical energy among different types of molecules following schemes that we call genetic due to their hereditability. The adhesion to genetic instructions may entail highly sophisticated and close to ineludible mechanisms (as in our human case), or may more simply be thought of as an ensemble of molecules elaborating chemical information, partly redirecting the intrinsic energy of their chemical structure, partly using the energy provided by the environment that they were able to harness and retain. Abiotic pre-metabolic cycles (Schwartz & Goverde, 1982; Weber, 2007; Morowitz et al. 2000; Smith & Morowitz, 2004) illustrate this point and provide an idea of the vitality of Darwin's pristine warm little pond. This scenario privileges the "metabolism-first" set of theories in contrast to the "geneticfirst" point of view. These Firsts, we have argued, needed not to be alternative and evolution on this planet was possibly kick-started by the cooperation of the different systems. The involvement of the protein world would require a discussion of its own.

Was it life?

From a point of view of rigorous logics, yes. No interruption in the evolutionary space going between these initial, as yet hypothetical but necessary, genetico-metabolic systems and the more complex (or, so to say, more genetically based) organisms may have taken place, by definition. Any interruption would have lead to a dead-end. Logically, going back in the evolutionary space (and, as far as we know, in time) means going back towards metabolic simplicity, means decreasing the dependence of life on genetic hereditability but does not allow to claim: after this point it was life, before it was not.

In this view we slide straight back into the pristine warm little pond, dipping into the mixture of organics that was allowed to leaven by the happy encounter of combinatorial chance and physical-chemical necessity. The principle of Continuity can be stated with no fear of contradiction for the very reason of our very existence.

5. THE STANDARD PRINCIPLES FOR LIFE: 2) SIMPLICITY

The prerequisite for life is the presence of the four most abundant elements: H, C, O and N (Spaans, 2005). The presence of sulphur S in proteins and in important metabolic nodes of extant organisms on planet Earth is indication of the sophisticated use of chemical alternatives but is metabolically marginal. The information-bearing elements of extant nucleic acids are held together by phosphate bridges. However, genetic chains built on different principles as PNA (Egholm et al. 1992) have provided the proof-of-principle for the existence of possible alternatives. It was suggested that phosphorus P can be replaced in its connecting functions by arsenic As (Wolfe- Simon et al. 2010).

The reactions of the four key elements in space result in a large panel of combinations. The site http://astrochemistry.net provides an idea of their combinatory power even in the harsh conditions they meet in space. If provided with the appropriate environment in terms of temperature, intensity and type of radiations, pressure, relative concentrations, stability of conditions, the catalogue of stable compounds is expected to skyrocket, based on the direct embodiment of the chemical potentialities of the 4 key atoms. The fact that carbon chemistry is particularly fertile is well known. The possibility that the chemistry of HCN has played a pivotal role in the initiation of biogenic reactions was proposed (Oró, 1961), extensively discussed (Orgel, 1998), brought to experimental verification (Saladino et al. 2009).

Simply warming formamide H₂NCOH (the product of the reaction of hydrogen cyanide HCN with water H₂O) in the presence of mineral catalysts of the most common sources (as reviewed in Saladino et al. 2010) results in a large panel of nucleic bases (Saladino et al. 2009), in acyclonucleosides (Saladino et al. 2003), in the phosphorylation of nucleosides (Costanzo et al. 2007). The non-enzymatic polymerization of cyclic nucleotides was reported (Costanzo et al. 2009), showing that the abiotic route from HCN to nucleic polymers is in principle possible in thermodynamically and kinetically sound simple conditions.

6. CONSCIOUSNESS AND THE STANDARD PRINCIPLES OF CONTINUITY AND SIMPLICITY

The interpretation of consciousness was given by R. Penrose as something that enables to perform actions that lie beyond any kind of computational activity (Penrose, 1988). The concept was extended (Penrose, 1994), such as to be applicable to any kind of computational process, implying "a mechanism in brain function whereby a non-computational physical action might indeed underlie our consciously controlled behavior". This mechanism is supposedly based on "subtle and largely unknown physical principles in order to perform the needed non-computational actions". The category of computation (or, more appropriately, its absence) is invoked as the key to understand the essence of consciousness.

Away from the idealized thermal equilibrium state, statistical fluctuations are expected (Penrose, 1994). Consciousness is thus located in the domain of the statistical behavior of matter, which is to say that consciousness is a property of statistical mechanics. This clearcut formulation brings to potentially testable ground a need expressed previously: We must postulate a cosmic order of nature beyond our control in which both the outward material objects and the inward images are subject (Pauli 1948); The same organizing forces that have shaped nature in all her forms are also responsible for the structure of our minds (Heisenberg 1971); Psyche and matter exist in one and the same world, and each partakes of the other (Jung 1970). The 26 years long correspondance between Pauli and Jung (Roscoe 2001) offers numerous examples of these intuitions. If one is allowed to boil down and intellectual correspondence encompassing all these years: the important things are born at the border between order and chaos. Is life computable? Computational models may describe biological systems. Undoubtedly, even though any organism as a whole is more complicated than a field of gravitating bodies or of any problem definable in Laplacean terms (from blood's flow to a human brain), "local" biological phenomena as organisms may be in principle computationally represented.

A different perspective arises if life is considered as a whole. Let us assume, based on what we know from planet Earth biology, that (i) on this planet no interruption of the reproducible flow of the coded complex biochemistry that we dub life has occurred since its emergence, and let us assume, based on what we know from astrochemistry, that (ii) the same potential for dynamic complexity is intrinsic in the reactivity of the components both of interstellar dusts and of their countless aggregation forms, anywhere they might occur. Let us in addition recognize that (iii) the chemistry of hydrogen H, of carbon C, of oxygen O, and of nitrogen N is the same all over the universe. Considered as a whole, the complexity of the potentially biotic chemistry is comparable to the complexity of the universe itself.

Taking into account the formal definitions of complexity, of emergence (and consequently acknowledging life as an emergent phenomenon), and considering the complexity of the reaction vessel involved (the universe itself), life is not computable. And taking also into account, as pointed out by R. Penrose, that "..chemical actions are the result of quantum effects, and [...] one has left the arena of classical physics when considering processes that are dependent upon chemistry" (Penrose, 1994).

Let us draw the logic conclusion from these considerations: gap-free flow of life is present everywhere in the universe in the form of more or less organized, more or less complex chemical reactions. Here we are conservatively limiting the definition of life to the flow of carbon-based reactions and we are implying that the lower limit of life are the processes involving the reactions of the one-carbon molecule HCN, considered as the starting and reactive clump of chemical information.

Can we apply to consciousness the standard principles of Simplicity and Continuity ? If so, we should acknowledge that : being consciousness the attribute of living entities, consciousness is present everywhere there is life in the universe.

Considering consciousness, we spontaneously start from our self-consciousness (which is typical of human beings, putting themselves at the center of every consideration). Like any other phenotype, consciousness is an evolutionary character. Thus the question can be asked about where and when, going back in evolutionary space, did consciousness come into being. Certainly our extant primate relatives are self-conscious, as other mammals have been shown to be. And how could we consider devoid of consciousness the eyes of a crow, or of a lizard? Is the reactivity of amoebas a sign of consciousness? Chapter 7 of (Penrose 1994) points out the implications of the quantic domain in neurophysiology, including the milestone observations in Paramecium. At which point the complex reactions of membranes, of photochemistry, of ion channels observed in protozoans start to differ from those of nervous cells of higher eukaryotes? Should the level of complexity be considered a categorical difference? And so on, backwards. As it is for life, drawing a line separating times before which there was no consciousness from those after which it came into being, is an arbitrary exercise.

Consciousness is considered as the attribute of the complex multicellular structure that we call human brain, and its root behaviour is deductively based on its ability to perturb matter at the quantic level (Penrose, 1988, 1994). Why should we be entitled to assume that simpler living structures do not perturb matter at the same quantic level, and why should we not draw from this the inescapable conclusion? Walking back in evolution, complexity decreases, but the limit of non-life and of non-reactivity is never reached. Drawing borders is a didactic, arbitrary act of our self-consciousness.

As for life, consciousness is an intrinsic property of reacting matter. In this living universe. Two principles are at the basis of contemporary philosophical quest, heavily overlapping with more or less speculative physics: the Observer's and the Anthropic Principles. The first states that physical entities cannot be observed without interfering with them, the second that we are here in this universe because its properties are just fit to allow our existence. A corollary of the Anthropic principle entails that other similar but not identical universes exist forming a sort of possible myriad doppelgangers of the only reality that we can observe. None of the two principles is in contradiction with the vision of life as a possible state of consciousness of the universe.

We may thus try to widen accordingly our parochial Euclidean horizon, extending the Gaia (Lovelock 1979) vision, and accept that life and consciousness are two aspects of the same rhizomatic phenomenon that encompasses the whole universe, and makes it so interesting.

Acknowledgments: we gratefully thank Silvia Lopizzo for helpful contributions.