We have pointed out that the psychic process is essentially finite and final, can we find any other process that should be characterized by the same mark of finiteness and finality? We find an analogous process in life. The life process is one that has the aspect of finiteness. Ontogenetically, the life-process of an organism has its beginning in the fertilization or stimulation to life-activity of the ovum, and has its end in death. Phylogenetically, the life process runs a determinate course. There was a time when geological conditions did not permit the presence of life, and there will come a time when life will be extinct. Ontogenetically, the biological process is analogous to the mental process. The biological process, unlike the physical process, is not endless; it has a definite beginning and end. Taking any stage of the process as the starting point, we find that neither the chain of antecedents, nor that of consequents can be followed endlessly. Being a finite process we find in it the same relation we discovered in the psychic process,―the first term of the series has no antecedent and the last one has no consequent. Furthermore, the biological process, like the psychological one, may be cut short at any stage,―the organism or the protoplasm may die or be killed. It is only mechanically regarded that the biological process can be worked into the definite texture of physical series.
The finiteness of the life process is especially manifested from the point of finality. In examining the character of living beings, in contradistinction to physical things, we find a fundamental difference between the two. The structure and function of living beings can be regarded under the concept of purpose or that of final causation, the purpose being the good, the advantage, the utility of the organism. Inanimate things cannot be regarded under the concept of final causation, but under that of efficient causation. The stone lying yonder has no purpose, it has no special advantage for its material particles from its particular position. The inner relations of its parts and the relations of its surface-angles and prominences are not of any ultimate good to the stone, nor do we ask of what use is this particular vibration to the molecules. We do ask, however, this question of utility in regard to organisms. Of what use is the grazing or drinking to the cow? Of what use is this particular organ and its function to this or that organism? The problem of utility is one that can only be raised in the case of organic life, but not in the case of inorganic things. We can see the reason why it should be so. Life may be regarded as an adaptation of inner and outer relations. Adaptation and fitness are important criteria with biological processes. What is the fitness, or utility of organs and their functions to the particular organism, and how have they come to this given state of fitness? These problems cannot be ignored by biology as a science. The whole of the Darwinian theory aims to give the key to the way the different forms of adaptations have come about. Adaptation and utility, however, mean aims. A biological process is not an endless series of antecedents and consequents, but one that has an end. A life process is a final process taking place in the organism in its internal and essential adjustments.
The finality of the life process is clearly brought out, if looked at from a totally different point of view. The most characteristic feature of a living organism, is its being an organic whole, a unity, an individuality. All the parts of the organism bear relation to and have their significance with regard to the organism as a whole. The fin of the fish, the wing of the bird, and the arm of the man cease to be what they are, if separated from the particular individual to which they respectively belong. The structure and function of the part can be understood only in relation to the needs of the organic whole. The parts of the individual subserve the organic unity. In the course of evolution, both ontogenetic and phylogenetic, parts may arise or drop out for the benefit and advantage of the whole. Mechanically considered, an organism is nothing but a heap of vibrating molecules or atoms; biologically regarded, this heap constitutes a whole, an individual, and each vibration is for the good of this whole, if the individual is to maintain itself in existence.