The phrase "contrary to reason" is often used to describe something as illogical, irrational, or unreasonable. However, there are several other synonyms that can be used to convey the same meaning. Words like senseless, preposterous, absurd, and nonsensical are all effective substitutes for the phrase "contrary to reason". Similarly, terms like irrational, illogical, and unreasonable are commonly used to describe a situation or idea that defies logic or reason. In general, these synonyms can be used interchangeably when trying to express the idea that something is not based on sound reasoning or evidence.