Wronger than wrong

It’s a little wrong to say a tomato is a vegetable, it’s very wrong to say it’s a suspension bridge. Wronger than wrong is a logical fallacy that occurs when it is asserted that different degrees of "right" or "wrong" are the same — a form of equivocation of degrees of truth.

The fallacy is a fallacy of ambiguity and an informal fallacy.

Explanation
[W]hen people thought the earth was flat, they were wrong. When people thought the earth was spherical, they were wrong. But if you think that thinking the earth is spherical is just as wrong as thinking the earth is flat, then your view is wronger than both of them put together. The phrase "wronger than wrong" was coined by Isaac Asimov in The Relativity of Wrong (expanded and popularised by Michael Shermer, who called it "Asimov's Axiom"). Wronger than wrong describes any idea that equates errors that clearly aren't equal. The example originally given is that a belief in a flat earth is wrong, but a belief in a spherical earth is also wrong (as it's actually an oblate spheroid) — however, saying that belief in a spherical or in a flat earth are equally wrong is more wrong than both those errors combined. Blurring concepts into the same category of "wrong" or "improbable", despite their obvious difference in the magnitude of how "wrong" and "improbable" they are, is an example of the continuum fallacy (the "fallacy of gray"). Another example to illustrate the difference is that it would be wrong to categorize bats as rodents but also to categorize bats as insects. However, bats as rodents is far less wrong as both are orders of mammals, and their superficial similarity to mice has led to a common misconception that bats and mice are related, an understandable mistake by someone who isn't well-read on the subject. However, categorizing bats as bugs is entirely wrong, arthropods and chordates are entirely different phyla and have very little in common with each other except that they're both part of the clade Nephrozoa.

Importance
This phrase has important implications regarding the nature of scientific theories and aptly describes how the scientific method builds up knowledge and understanding — theories may change and adapt, but calling them outright wrong is not necessarily the right way to go about it. One reviewer of Asimov's The Relativity of Wrong asserted that such thinking was a great tool for "arming oneself against the inevitable anti-science attack that one often hears — [that] theories are always preliminary and science really doesn't 'know' anything".