In point of fact, many stimuli are beneath the " threshold " of a man's consciousness.
The threshold-value of the stimuli adequate for the various senses may be extraordinarily lowered.
By the rules of induction from concomitant variations, we are logically bound to infer the realistic conclusion that outer physical stimuli cause inner sensations of sensible effects.
Breath holding spells are episodes of brief, involuntary cessations of breathing that occur in children in response to stimuli such as anger, frustration, fear, or injury.
This theory of complementary colours as due to the polarity in the qualitative action of the retina is followed by some criticism of Newton and the seven colours, by an attempt to explain some facts noted by Goethe, and by some reference to the external stimuli which cause colour.
