Lettvin considered any experiment a failure from which the experimental animal does not recover to a comfortable happy life.
He was one of the very few neurophysiologists who successfully recorded pulses from unmyelinated vertebrate axons.
His main approach to scientific observation seems to have been reductio ad absurdum, finding the least observation that contradicts a key assumption in the proposed theory.
This led to some unusual experiments.
In the paper "What the Frog's Eye Tells the Frog's Brain", he took a major risk by proposing feature detectors in the retina.
 When he presented this paper at a conference, he was laughed off the stage by his peers, yet for the next ten years it was the single most cited scientific paper.
 For Lettvin, a corollary to finding contradictions was taking risks: the bigger the risk, the likelier a new finding.
Robert Provine quotes him as asking, "If it does not change everything, why waste your time doing the study?"

Lettvin made a careful study of the work of Leibniz, discovering that he had constructed a mechanical computer in the late 17th century.

Lettvin is also known for his friendship with, and encouragement of the cognitive scientist and logician Walter Pitts, a polymath who first showed the relationship between the philosophy of Leibniz and universal computing in "A Logical Calculus of Ideas Immanent in Nervous Activity," a seminal paper Pitts co-authored with Warren McCulloch.

Lettvin continued to research the properties of nervous systems throughout his life, culminating in his study of ion dynamics in axon cytoskeleton.
Lettvin considered any experiment a failure from which the experimental animal does not recover to a comfortable happy life. He was one of the very few neurophysiologists who successfully recorded pulses from unmyelinated vertebrate axons. His main approach to scientific observation seems to have been reductio ad absurdum, finding the least observation that contradicts a key assumption in the proposed theory. This led to some unusual experiments. In the paper "What the Frog's Eye Tells the Frog's Brain", he took a major risk by proposing feature detectors in the retina.  When he presented this paper at a conference, he was laughed off the stage by his peers, yet for the next ten years it was the single most cited scientific paper.  For Lettvin, a corollary to finding contradictions was taking risks: the bigger the risk, the likelier a new finding. Robert Provine quotes him as asking, "If it does not change everything, why waste your time doing the study?"
Lettvin made a careful study of the work of Leibniz, discovering that he had constructed a mechanical computer in the late 17th century.
Lettvin is also known for his friendship with, and encouragement of the cognitive scientist and logician Walter Pitts, a polymath who first showed the relationship between the philosophy of Leibniz and universal computing in "A Logical Calculus of Ideas Immanent in Nervous Activity," a seminal paper Pitts co-authored with Warren McCulloch.
Lettvin continued to research the properties of nervous systems throughout his life, culminating in his study of ion dynamics in axon cytoskeleton.
Jerome Lettvin