However, it is important to notice something about materialist philosophies. They not only believe that the world is material, they also perforce believe that the truth about that material world can be discovered, and is being discovered, by people in the sciences, and that, furthermore, there are philosophical arguments that ought to persuade people to eschew mentalistic worldviews in favor of materialistic ones. They do think that we can better discover the nature of the world by observation and experimentation than by reading tea leaves. Arguments from reason are arguments that appeal to necessary conditions of rational thought and inquiry. Thus, they have what on the face of things is an advantage over other arguments, in that they have a built-in defense against error theory responses. If there is no truth, they cannot say that materialism is true. If there are no beliefs, then they cannot say we ought to believe that materialism is true. If there is no mental causation, then they cannot say that our beliefs ought to be based on supporting evidence. If there are no logical laws, the we cannot say that the argument from evil is a good argument. If our rational faculties as a whole are unreliable, then we cannot argue that the religious beliefs are formed by irrational belief-producing mechanisms. Hence, arguments from reason have what I call a transcendental impact — that is, appeal to things that, if denied, undermine the most fundamental convictions of philosophical materialists.