The genetic fallacy creates an argument that is accepted or rejected based on the source of the evidence, rather than on the quality or applicability of the evidence. It is also a line of reasoning in which a perceived defect in the origin of a claim or thing is taken to be evidence that discredits the claim or thing itself.

Essentially, the genetic fallacy is the broad grouping of several other fallacies including argumentum ad hominem and argument from authority, which attempts to misdirect the line of reasoning by invoking the origins of a claim, rather than the quality of evidence.

There are some cases where this fallacy may not be a fallacy — for example, when the source of the claim may be disputed or accepted if it is relevant to the quality of the evidence.

Examples of the Genetic fallacy

When it is a fallacy:

1. Andrew Wakefield said that vaccines cause autism.
2. Wakefield is a man of vision.
3. Vaccines cause autism must be true.

When it is not a fallacy:

1. Andrew Wakefield said that vaccines cause autism.
2. Wakefield lost his medical license, his articles have been retracted, and he is a grifter.
3. Vaccines cause autism must not be true.