In Latin "Ad Hominem" means "against the man" or "against the person."
A theory is discarded not because of any evidence against it or lack of evidence for it, but because of the person who argues for it. is rejected on the basis of some irrelevant fact about the person , making the claim or argument.
This argument is typically done as a two step process. First an attack is made against the character, circumstances, or actions of the person. This attack is then taken as evidence against the claim or argument the person is making.
- Person A makes claim X.
- Person B attacks the character, circumstances, or actions of person A (And this is taken as evidence against the claim)
- Therefore the claim made by person A is false.
A: The Government should enact minimum-wage legislation so that workers are not exploited.
B: Nonsense. You say that only because you cannot find a good job.
- You can't believe Jack when he says there isn't any God because he doesn't even have a job.
- Candidate Jane Jones' proposal X is ridiculous. She was caught cheating on her taxes in 2003.
- Chidambaram doesn't know how to make the economy boom. He barely won by 300 votes in the election.
- How can Rahul Gandhi help the poor? He was born rich
- How can you trust Arvind Kejriwal to be honest ? He ran away from governance in 49 days?
- How do you conclude Prof Bala is a great scientist ? He couldn't even pass a moral science test in school
An Ad Hominem is a general category of fallacies in which a claim or argument is rejected on the basis of some irrelevant fact about the author of or the person presenting the claim or argument. Typically, this fallacy involves two steps. First, an attack against the character of person making the claim, her circumstances, or her actions is made (or the character, circumstances, or actions of the person reporting the claim). Second, this attack is taken to be evidence against the claim or argument the person in question is making (or presenting). This type of "argument" has the following form:
Person A makes claim X
Person B makes an attack on person A.
Therefore A's claim is false.
The reason why an Ad Hominem (of any kind) is a fallacy is that the character, circumstances, or actions of a person do not (in most cases) have a bearing on the truth or falsity of the claim being made (or the quality of the argument being made).
Example of Ad Hominem
Bill: "I believe that abortion is morally wrong."
Dave: "Of course you would say that, you're a priest."
Bill: "What about the arguments I gave to support my position?"
Dave: "Those don't count. Like I said, you're a priest, so you have to say that abortion is wrong. Further, you are just a lackey to the Pope, so I can't believe what you say."