Tertullian

“ Now, if both one and the other could possibly have been accomplished without the soul, to breathe might not be a function of the soul, but merely to live. But indeed to live is to breathe, and to breathe is to live. Therefore this entire process, both of breathing and living, belongs to that to which living belongs—that is, to the soul. Well, then, since you separate the spirit (or breath) and the soul, separate their operations also. Let both of them accomplish some act apart from one another—the soul apart, the spirit apart. Let the soul live without the spirit ”

“ Some maintain that there is within the soul a natural substance—the spirit—which is different from it: [3] as if to have life—the function of the soul—were one thing; and to emit breath—the alleged [4] function of the spirit—were another thing. Now it is not in all animals that these two functions are found; for there are many which only live but do not breathe in that they do not possess the organs of respiration—lungs and windpipes. ”

“ I suppose it means to emit breath from yourself. What is it not to live? I suppose it means not to emit breath from yourself. This is the answer which I should have to make, if “to breathe” is not the same thing as “to live.” It must, however, be characteristic of a dead man not to respire: to respire, therefore, is the characteristic of a living man. But to respire is likewise the characteristic of a breathing man: therefore also to breathe is the characteristic of a living man. ”

“ But of what use is it, in an examination of the soul of man, to borrow proofs from a gnat or an ant, when the great Creator in His divine arrangements has allotted to every animal organs of vitality suited to its own disposition and nature, so that we ought not to catch at any conjectures from comparisons of this sort? Man, indeed, although organically furnished with lungs and windpipes, will not on that account be proved to breathe by one process, and to live by another ”

“ You would thus supply yourself with a strong proof that the spirit or breath is an adjunct of the human soul, for the very reason that some creatures lack breath, and that they lack it because they are not furnished with organs of respiration. You think it possible for a thing to live without breath ”

“ If it is by such instruments that life is maintained, these instrumental means must of course exist in all things which are to live, even though they are not apparent to the eye or to the apprehension by reason of their minuteness. ”

“ Take any living thing whatever, be it the tiniest you can find, it must needs be fed and sustained by some food or other: show me, then, their organs for taking into their system, digesting, and ejecting food. ”

“ I have my doubts whether he succeeded in clearly exploring all the internal parts of their structure, since death itself changes and disturbs the natural functions of life, especially when the death is not a natural one, but such as must cause irregularity and error amidst the very processes of dissection. Philosophers have affirmed it to be a certain fact, that gnats, and ants, and moths have no pulmonary or arterial organs. ”

“ If, however, you suppose that God’s wisdom has no capacity for forming such infinitesimal corpuscles, you can still recognise His greatness, in that He has furnished even to the smallest animals the functions of life, although in the absence of the suitable organs,—securing to them the power of sight, even without eyes ”