Lin
243
LIFE
podue«d to form quite other parte of the organion
ihan thoee for which they were normally designed.
This proves that there must be in the original cell a
flexible formative power capable of directing the vital
proceeaea of the embryo along the most devious paths
and of adapting mucn of its constituent material to
the most diverse uses.
(3) Pmfchical Argument. — Finally, we have imme- diate ancf intimate knowledge of our own living con- scious unity. I am assured that it is the same ulti- mate principle within me which thinks and feels, which originates and directs my movements. It is this same principle which has eovcmed the growth of aU my sense-organs and members, and animates the whole of mv body. It is this which constitutes me one rational, sentient, Uving being.
All these various classes of facts prove that life is not explicable by the mechanical, physical, and chem- ical properties of matter. To account for the phe- nomena there is required within the living being a principle which has built up the organism after a defi- nite plan; which constitutes the manifold material a single being; which is intimately present in every part of it; which is the source of its essential activities; and which determines its specific nature. Such is the vital principle. It is therefore in the Scholastic ter- minology at once the final, the formal, and even the efficient cause of the livine being.
C. Unity of the Living Being. — In each animal or plant there is only one vital principle — one substan- tial form. This is obvious from the manner in which the various vital functions are controlled and directed to one end — ^the good of the whole being. Were there more than one vital principle, then we should have not one being but a collection of beings. The prac- tice of abstraction in scientific -descriptions and dis- cussions of the structure and functions of the cell has sometimes occasioned exaggerated notions as to the independence and separateness of existence of the individual cell, in the organism. It is true that cer- tain definite activities and functions are exercised by the individual cell as by the eye or the liver; and we may for convenience consider these in isolation : but in concrete reality the cell, as well as the eye or the liver, exerts its activity by and throueh llie Ii\ing energy of the whole bein^. In some lowly organisms it is not easy^ to determine whether we are in presence of an individual being or a colony; but tliis docs not affect the truth of the proposition that the vital principle being the substantial form, there can only l^e one such principle animating the living being. With res{)ect to the nature of this unity of form there has been much dispute among the adherents of the Scholastic phi- losophy down to the present dav. It is agreed that in the case of man the unity, which is of the most perfect kind, is founded on the simplicity of the rational or spiritual soul. In the case of the higher animals also it has been generally, though not universally held that the vital principle is indivisible. With respect to
1>lants and lower forms of animal life in which the parts ive after division, the disagreement is considerable. According to some writers the vital principle here is not simpfe but extende<l, and the unity is clue merely to its continuity. According to others it is actually simple, potentially manifold, or divisible in virtue of the nature of the extended organism which it ani- mates. There does not seem to be much prospect of a final settlement of the point. (Urraburu, "Psy- chologia", bk. I.)
D. UUimaie Orimn of Li/p.— The whole weight of the evidence from biological investigation during the last fifty years, as we have already obsrrved, goes to prove with constantly increasing force that life never appears on the earth except as originating from a previous living being. On the other hand science also proves that there was a time in the past when no life ccndd have posribly existed on this planet. How then
did it begin? For the Christian and the Theist ths
answer is easy and obvious. Life -must in the first
instance have been due to the intervention of a living
First Cause. When Weismann says that for him the
assumption of spontaneous generation is a "logical
necessity" (Evolution Theory, II, 366), or Ivarl Pear-
son, that the demand for " special creation or an ultra-
scientific cause" must be rejected because "it would
not bring unity into the phenomena of life nor enable
us to economize thought (Grammar of Science, 353),
we have merely a psychological illustration of the
force of prejudice even in the scientific mind. A bet-
ter sample of the genuine scientific spirit and a view
more consonant with actual evidence are presented to
us by the eminent biologist, Alfred Russel Wallace,
who, in concluding his discussion of the Darwinian
theory, points out "that there are at least three stages
in the development of the organic world when some
new cause or power must necessarily have come into
action. The nrst stage is the change from inorganic
to organic, when the earliest vegetable cell, or the liv-
ing protoplasm out of which it arose, first appeared.
This is often imputed to a mere increase of complexity
of chemical compounds; but increase of complexity,
with consequent instability, even if we admit that it
may have produced protoplasm as a chemical com-
pound, could certainly not have produced living pro-
toplasm — protoplasm which has the power of growth
and of reproduction, and of that continuous process of
development which has resulted in the marvellous
varietv and complex organization of the whole vege-
table kingdom. There is in all this something quite
beyond and apart from chemical changes, however
complex; and it has been well said that the first
vegetable cell was a new thing in the world, possessing
altogether new powers — ^that of extracting and fixing
carbon from the carl)on dioxide of the atmosphere,
that of indofmite reproduction, and still more marvel-
lous, the ix)wcr of variation and of reproducing those
variations till endless complications of structure and
varieties of form have l)een the result. Here, then,
we have indicat ions of a new power at work, which we
may term vilalitt/, since it gives to certain forms of
matter all those characters and properties which
constitute Life" (*' Darwinism", London, 1889,474-5).
For a discussion of the relation of life to the law of
the conservation of energy, see Eneroy, where the
question is treated at length.
Having thus expounded what we believe to be the teaching of the l)est recent science and philosophy respecting the nature and immediate origin of life, it seems to us most important to bear constantly in mind that the Catholic Church is committed to extremely little in the way of positive definite teaching on the subject. Thus it is well to recall at the present time that three of the most eminent Italian Jesuits, in phi- losophy and science, during the nineteenth century. Fathers Tongiorpi, Secchi, and Palmieri, recognized as most competent theologians and all professors in the Gregorian University, all held the mechanical theor>' in regard to vegetative life, whilst St. Thomas and the entire body of theologians of the Middle A^es, like everylwdy else of their time, believed implicitly in spontaneous generation as an evcr\'day occurrence. If therefore these decay e<l scientific hypotheses should ever l>e rehabilitated or — which does not seem likely — lx> even established, there would l>e no insuperable diflficulty from a theological standpoint as to tneir ac- ceptance.
Many articles deal with questions toiirhr<l upon in the present fluhjeot: Actus et Potentia; Bioc.enehis: Huhxkjy; Enerot; Evoli'tion; Form: Matter. The iB;eneraI literature is solaiiKe our selection must do somewhat nrbftrarj'.
Historical. — Aristotle, DeAnimn, tr. Hammond (Ix>ndon, 1902); also tr. Hk'kr; Idem, De Generations Animalium; De Hifitoria Ammalium, tr. Ores well; St. Thomas. I, Q. Ixxvi, and paasim; Uolfes, Die SubstanliaU' Form und der Begriffder Sccle bri AridoUleH (Faderbom, 1800); Bouilurr, Du Prin- cipe vital et de Vdme jfenaante (Pam, \Hfik^\ VJi^x-is^ca., \>rr
