The Cartesian masculinization of thought begins with the separation of the self from the external world, separation from the mother and correspondingly, mother earth.
Descartes describes his uncertainty about the external world. His only certainty is that he exists (cogito ergo sum). Therefore, he requires God (the Father) to prove that things, or more specifically the essence of things, exist and/or continue to endure. In separating the self from the world, Descartes proposes that we become (paradoxically) less certain of the existence of the external world (like a child who has not yet developed object permanence) and yet more objective.
Susan Bordo suggests that the Cartesian era brought a more decisive separation between the inner (mental) world and the external (sensible) world. She argues that prior to the Cartesian masculinization of thought, the idea of this separateness was not considered. She finds evidence of this in medieval art where objects are grouped together, often in mosaic patterns that reflect an implication that prior worldviews did not need to consider a person's separation from the external world. It was inherent that human and world were necessarily connected. The Cartesian separation of mind and world changed this perception but also created an anxiety (how can I prove that the external world exists?). Descartes justifies the ontological existence of external things by invoking God's omniscience and timelessness.
With this sense of separation of mind and body, Descartes sought to establish philosophy as an objective science, one which evades the fallibility of the senses and certainly one that is not in touch with emotions or other such associations. The result is a philosophy in which bodies are machines, and the natural (and spiritual) connections with earth and the cosmos are severed. The earth and the cosmos, from which life itself emerges (as if from a womb) are objectified; the organic and ecological sense of "all things being connected" is lost.
This separation also parallels the separation from the mother to become, as Bordo puts it, “the father of one's self.” In separating this way, the subject can look at the world and understand it, not in terms of his connection with the world, but objectively. Separating this masculine self from the feminine mother earth, Descartes takes the subject out of union with nature. Viewing the self as the certain stuff of life and the external world as an illusion or a lifeless mechanism, those external objects became anything “other” than the self “I.” Women and minorities fave suffered the same compartmentalizing as being “other,” objects to be studied, not sympathized with and not to be connected with.
Finally, the historical construction of what it is to be male, since Descartes, has been described like the Cartesian self; distanced, detached, objective, and rational. As a result, women have often been described as emotional and intuitive. Bordo suggests that this historical masculinization of the way men and women think established or continued a historical precedent that men are objective, scientific and women are not. These gender roles are cultural constructions; not biological essences. The point Bordo makes is that this philosophy of objectification excludes an organic, traditionally viewed "feminine" perspective, but this objective separation is also what allows the philosopher to objectify and categorize gender roles (and thought) in misogynistic terms.