Emotion usually has been regarded as subversive of knowledge and investigation, and reason generally has been regarded as the indispensable faculty for acquiring knowledge. In this context, reason typically has been contrasted with emotion, and this contrast has been linked with other dichotomies. Not only has reason been contrasted with emotion, but it has also been associated with the mental, the cultural, the universal, the public, and the male, whereas emotion has been associated with the physical, the natural, the particular, the private, the irrational and the female.
However, it is important to acknowledge the importance of emotion for knowledge and investigation. It's because emotion as well as reason reflects an aspect of human knowing, and each is inseparable from the other. And it is also important to note that the alienation of emotion in human knowing is intimately related to the sexism. This fact shows us the ideological function of the principle of the objective validity in theory and investigation.