Carus, Physiological Condition of Consciousness. 133 



ganization and nothing but one idea, one purpose, or one action 

 can at a time be illuminated by that state of mind which we 

 call consciousness. The reason which we can find for it lies in 

 the fact that consciousness is nothing but feeling in the focus of 

 attention ; and attention is concentration or unification, which 

 latter is imposed upon a mind by the need of a concerting co- 

 operation of all the organs of an organism in pursuing a spec- 

 ial purpose. 



Now the question is, What is the physiological condition 

 of this psychical unification of feelings? How is the converg- 

 ence of attention attained ? 



I do not mean to enter into details, nor do I wish to re- 

 peat myself, but it seems to me certain that the hemispheres 

 are constantly doing an enormous amount of cerebration which 

 remains utterly unconscious. Hemispheric activity, accord- 

 ingly, cannot eo ipso constitute consciousness. The problem 

 is, What additional function raises the work of one hemispheric 

 structure into the sphere of all-dominant attention ; and I be- 

 lieve that the corpora striata piay an important role in the con- 

 summation of consciousness. They are ontogenetically a part 

 of the hemispheres and are very early differentiated from the 

 cortex. Their tissue is usually delicate and richer in capil- 

 lary blood vessels than any other part of the brain. In addi- 

 tion to the fibres that pass through them, there are connexions 

 with the hemispheres. The corpora striata possess terminal 

 stations similar to those in the cortex, and from them the decus- 

 sating pyramidal tracts of involuntary motions start, while the 

 involuntary reflexes possess paths of their own directly descend- 

 ing from the thalamus. What is a voluntary motion if not a 

 consciously willed reflex? To say, as Meynert does, on the 

 basis of undisputed anatomical and physiological facts, that the 

 corpus striatum is a ganglion of voluntary motion, implies that 

 it is nothing but a deliberate preparation for action, i.e., volun- 

 tary motion. 



In addition to these arguments, it is noteworthy that the 

 development of the coi^pora stiiata is always proportionate to 

 the cortical development. Meynert made the observation that 



