(The Right Hon. A.J. Balfour.)
This is the "transmissive" as opposed to the "productive" theory and the whole position is very like that which obtained in Psychology some years ago. William James then showed that although it was possible to interpret the observed facts of Psychology on the hypothesis that the brain "produced" consciousness it was equally legitimate to do so on the hypothesis that it "transmitted" it.
As he said " ... Mere coincidence in two sets of phenomena does not prove that they are causally connected, that one produces the other. They may be quite separate from one another (psycho-physical parallelism) or both may be aspects of something else."
Personally I should be prepared to admit only the latter possibility. Causeless parallelism is incredible; as James himself admits elsewhere.
The analogy is very close. Just as consciousness is usually conceived to be due to the functioning of the brain but may, on the contrary exist apart from it and merely use the brain as a channel of manifestation, so also may Life exist apart from and use the body.
I will not go into the various arguments which support this view. Perhaps the most striking is that from the necessity for sleep—a phenomenon which appears to be exclusively associated with Life. A mechanism needs replenishing with fuel, it must have worn parts replaced and both these processes are accurately paralleled in the body of any living organism. But an engine does not need sleep, whereas a living organism not only needs it but cannot be satisfied with any substitute for it. It looks therefore as if Life could not be maintained from purely physical sources and this lends support to the view that it is an essentially extra-physical thing transmitted by, but not arising from, physical actions.
But this view leaves us with the difficulty that if we suppose that Life is transcendent to the Physical and uses it only as a means of manifestation we cannot see how it can do so without partaking of the nature of the physical and so losing its "selective," "guiding" or "intelligent" qualities. For in order that things should be causally connected they must have qualities in common. Are then we to say that life is a form of energy or that it is not?
As Mr. Carrington says: "We are ... driven into this dilemma: life must be an energy—but, as such, it cannot be purposive! Life is purposive, yet it must be an energy—for otherwise it could not affect the bodily energies and the material world."
M. Bergson adopts the "hair trigger" theory and supposes the Life only affects the physical energies of the body very slightly, just enough to deflect them this way or that. But this is not getting out of the difficulty at all, for the problem is one not of degree but of kind; it is just as difficult to imagine "non-energy" affecting energy "very slightly" as to imagine it affecting it a good deal.