Although section 2(b) of the Canadian Charter of Rights and Freedoms specifies the fundamental freedoms of ‘thought, belief, opinion and expression, including freedom of the press and other media of communication’, only freedom of expression has been developed by the courts. These forgotten freedoms include freedom of thought. This chapter demonstrates how Canada’s own constitutional text and history supports a new recognition of freedom of thought that would overcome a recent history of forgetting this constitutional freedom. Canada’s own constitutional case law, read creatively, contains the seeds of a framework for freedom of thought, with upcoming potential to put arguments before the courts in cases where significant litigation efforts will be made. This chapter sets how the Canadian Charter protects specific elements of the right which are mental privacy, mental liberty and mental autonomy. The contemporary debate within the present international discussion generates an intellectual atmosphere and comparative case law that can support a remembering of the forgotten freedom of thought.