Slusher’s most influential contributions to pseudoscience are probably his attempts to explain away the presence of impact craters on nearly all solar system objects, which naturally creates rather insuperable problems for the Young Earth position. Slusher, with Richard Mandock and Glenn Morton (who later repudiated this claim ), claimed that impact craters on the moon are subject to rock flow, and so cannot be more than a few thousand years old. In other words, they were created during … the Flood. This is not a mainstream scientific position. Slusher’s 1971 paper in Creation Research Society Quarterly claiming that there was not as much cosmic dust on the moon as would be expected if it was 4.5 billion years old, was also widely influential (Kent Hovind used that one quite a bit). Even Answers in Genesis admits that it relies on measurement inaccuracies, however.
Diagnosis: Like we said: a grand old man of pseudoscience who has devoted his life to spreading falsehoods and making the world a worse place to live. He’s pretty old now, though he will probably never realize what kind of crap he devoted his life to. Sad.