I. Haeckel and His Opponents

The totality of human soul-activities, which find their highest expression in unitary self-consciousness, corresponds to the complex structure of the human brain,[^5] just as simple feeling and willing do to the organisation of the protozoa. The progress of physiology, which we owe to investigators like Goltz, Münk, Wernicke, Edinger, Paul Flechsig, and others, enables us to-day to assign particular soul-manifestations to definite parts of the brain as their special functions. We recognise in four tracts of the grey matter of the cortex the mediators of four kinds of feeling: the sphere of bodily organic feeling in the meso-cranum lobule, that of smell in the frontal lobule, that of vision in the chief basal lobule, that of hearing in the temple lobule. The thinking which connects and orders the sensations has its apparatus between these four “sense-foci.” Haeckel links the following remark to the discussion of these latest physiological results: “The four thought-foci, distinguished by peculiar and highly complicated nerve-structure from the intervening sense-foci, are the true organs of thought, the only real tools of our mental life” ( On our Present Knowledge as to the Origin of Man, P-15).