Without resorting to a detailed review and debate of scientific studies (which I have done elsewhere on this site), it is still possible to evaluate claims that vaccines are the cause of some, many, or most cases of autism, all of which claims have been made. The use of logic is the key to this critique. Logic is a way of evaluating and classifying arguments and propositions. It uses formal structures that have evolved over millennia to determine the validity of arguments and consider whether arguments contain fallacies. While the ‘vaccines cause autism’ hypothesis (and its various components) is an argument / series of arguments about science and therefore an appropriate topic for scientific comment, it also still an argument, and therefore can be also be evaluated logically, by persons not formally trained in science.

This section discusses vaccines and the theory they cause autism generally. There are more specific discussions of the various vaccine / autism theories on other sub-pages on this Vaccines and Autism page, such as the theory that it is the thimerosal in certain vaccines that is causing autism.

There are two parts to this section. The first addresses logical flaws in many of the arguments that causally tie vaccines and autism. The second addresses the biases that seem to be present in many of those making these arguments, and describes how these biases likely contribute to the logical flaws discussed in the first part.