This is a quote from the book "The Virtue Of Selfishness" by Ayn Rand
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The range of actions required for the survival of the higher organisms is wider: it is proportionate to the range of their consciousness. The lower of the conscious species possess only
the faculty of sensation, which is sufficient to direct their actions and provide for their needs. A sensation is produced by the automatic reaction of a sense organ to a stimulus from the outsi
de world; it lasts for the duration of the immediate moment, as long as the stimulus lasts and no longer. Sensations are an automatic response, an automatic form of knowledge, which a consciousn...