Page:Theory of Mind of Roger Bacon.djvu/44

 that he had given his attention far less to these details than he had to the broad sketching of the theory; and also there is inherent in the theory that element of parallelism which would really have made impossible the interaction which he conceived. Let us make this clear by reference to certain examples.

For the mutual influence of the Earth and the Heavenly bodies, we have seen that it was not really the eduction theory which was applicable, but the emission theory in its refined form. In so far then as he meant the eduction theory of Species to be applied to this mutual influence, what he intended was not possible. And further he has here left obscure a most important point, in spite of the fact that he again and again gives us evidence of his intention of applying the theory in this field. Namely, the influence of the Heavens in producing life and in affecting character. If this theory is to hold at all here, it must be by the modified emission theory and not by the eduction theory of generation. The Sun, for example, has a generative heat but also a vital heat as well; and so its life-giving Species would generate life. But the life-giving element in the sun is not life, but heat; and no explanation lies in the combination of “generativam et vitalem” to account for the production of life out of heat. And in the case of the human being, the human soul of the parent is also auxiliary in producing this life. Here, then, is an important instance where his failure to explain the equivocal effects is serious. Further, how can a hot and dry sun so act upon man as to produce good character instead of bad, or a man of affairs rather than a student? Bacon can reply only generally in these terms: The air about us is filled with the virtues of the Sun, and this air as assimilated to the Sun acts upon our physical bodies and changes them. In turn the body acts upon the soul and changes it. And so men are made to wish what they had not wanted to wish, and not to desire what they had previously desired. Here then the corporeal Species has in so far as it is the bona fide factor in the process of assimilation, become somehow spiritual. A parallelism has passed over into an interactionism, as it were.

Or, to take the reverse of this. He tells us that Nature obeys the thoughts of the mind. And in such wise that the willing of a certain corporeal effect will produce that effect. And, to take the case only of the sensitive soul, he cites the instance, as given by Avicenna, of a fighting cock which though victorious had lost its