Thomas Lewis said this quote

A person cannot direct his emotional life in the way he bids his motor system to reach for a cup. He cannot will himself to want the right thing or to love the right person or to be happy after a disappointment, or even to be happy in happy times. People lack this capacity not through a deficiency of discipline but because the jurisdiction of will is limited to the latest brain and to those functions within its purview. Emotional life can be influenced, but it cannot be commanded.

~ Thomas Lewis

But dividing the mind into “biological” and “psychological” is as fallacious as classifying light as a particle or a wave. The natural world makes no promise to align itself with preconceptions that humans find parsimonious or convenient. (167)

~ Thomas Lewis

The emotional mind likewise transcends the facile and appealing dualism separating its psychological and biological aspects. Physical mechanisms produce one’s experience of the world. Experience, in turn, remodels the neurons whose chemoelectric messages create consciousness. Selecting one strand of that eternal braid and assigning it primacy is the height of capriciousness. (168)

~ Thomas Lewis

When people have trouble with their emotions – a bout of anxiety or depression, say, or seasonal gloominess - they often want science to pinpoint an offending neurotransmitter in the way that a witness picks the perp out of a lineup. Is it excessive norepinephrine, too little dopamine, errant estrogen? The answer is apt to dissatisfy: no single suspect can be fingered with confidence because the question itself attributes a fallacious simplicity to the brain.(91)

~ Thomas Lewis