Self Comes to Mind
kinds of tissue so as to constitute organs, and connecting different organs so as to form systems. Examples of tissues include the epithelia of skin, mucosal linings and endocrine glands, the muscular tissue, the nervous or neural tissue, and the connective tissue that binds them all in place. Examples of organs are obvious, from hearts and guts to the brain. Examples of systems include the ensemble formed by the heart, blood, and blood vessels (the circulatory system), the immune system, and the nervous system. As a result of this cooperative arrangement, our organisms are highly differentiated combinations of trillions of cells of varied kinds, including, of course, neurons, the most distinctive constituents of the brain. More about neurons and brains in a minute.
The main difference between the cells found in multicellular (or metazoan) organisms and the cells of unicellular organisms is that while single cells must fend for themselves, the cells that constitute multicellular organisms live within highly diverse, complex societies. Many of the tasks that the cells of unicellular organisms must accomplish alone are, in multicellular organisms, assigned to specialized cell types. The general arrangement is comparable to the diverse assignment of functional roles that each individual cell embodies in its own structure. Multicellular organisms are made of multiple, cooperatively organized unicellular organisms, which first arose from the combination of even smaller individual organisms. The economy of a multicellular organism has many sectors, and the cells within those sectors cooperate. If this sounds familiar and makes you think of human societies, it is because it should. The resemblances are staggering.
The governance of a multicellular organism system is highly decentralized, although it does have leadership centers with advanced powers of analysis and decision, like the endocrine system and the brain. Still, with rare exceptions, all the cells in multicellular organisms, ours included, have the same components as those of a single one—membrane, cytoskeleton, cytoplasm, nucleus. (Red blood cells, whose brief, 120-day life is devoted to transporting hemoglobin, are the exception: they have no nucleus to speak of.) Moreover, all those cells have a comparable life cycle—birth, development, senescence, death—as does a big organism. The life of a single human organism is built of multitudes of simultaneous, well-articulated lives.
As simple as they were and are, single cells had what appeared to be a decisive, unshakable determination to stay alive for as long as the genes inside their microscopic nucleus commanded them to do so. The governance of their life included a stubborn insistence to remain, endure, and prevail until such time as some of the genes in the nucleus would suspend the will to live and allow the cell to die.
I know it is difficult to imagine that the notions of “desire” and “will” are applicable to a single lonely cell. How can attitudes and intentions that we associate with the conscious human mind, and that we intuit to result from the workings of big human brains, be present at such an elementary level? But there they are, by whatever name you may wish to call those features of the cell’s behavior. 3
Deprived of conscious knowledge, deprived of access to the byzantine devices of deliberation available in our brains, the single cell seems to have an attitude: it wants to live out its prescribed genetic allowance. Strange as it may seem, the want, and all that is necessary to implement it, precedes explicit knowledge and deliberation regarding life conditions, since the cell clearly has neither. The nucleus and the cytoplasm interact and carry out complex computations aimed at keeping the cell alive. They deal with the moment-to-moment problems posed by the living conditions and adapt the cell to the situation in a survivable manner. Depending on the environmental conditions, they rearrange the position and distribution of molecules in their interior, and they change the shape of subcomponents, such as microtubules, in an astounding display of precision. They respond under duress and under nice treatment too. Obviously, the cell components carrying out those adaptive adjustments were put into place and instructed by the cell’s genetic material.
We commonly fall into the trap of regarding our big brains and complex conscious minds as the originators of the attitudes,
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