Descartes’ unexamined assumption that genuine science must take the form of a deductive, geometrical… — Edmund Husserl

Descartes’ unexamined assumption that genuine science must take the form of a deductive, geometrical system—resting ordine geometrico on axioms such as the ego’s self-certainty—was a ‘fateful prejudice’ that secretly shaped his Meditations and subsequent philosophy, and this model must not determine phenomenological thinking.

By Edmund Husserl, from Cartesian Meditations

Key Arguments

Husserl points out that Descartes “presupposed an ideal of science, the ideal approximated by geometry and mathematical natural science,” identifying a specific historical model that guided Descartes.
He calls this inherited geometrical-scientific ideal “a fateful / prejudice” that “determines philosophies for centuries and hiddenly determines the Meditations themselves,” suggesting its deep and largely unnoticed influence on modern thought.
Husserl notes that for Descartes “it was … a truism from the start that the all-embracing science must have the form of a deductive system, in which the whole structure rests, ordine geometrico, on an axiomatic foundation that grounds the deduction absolutely,” reconstructing Descartes’ ideal of systematicity.
Within this framework, “a role similar to that of geometrical axioms in geometry is played in the all-embracing science by the axiom of the ego’s absolute certainty of himself, along with the axiomatic principles innate in the ego,” so that the cogito becomes an axiom at the base of a deductive edifice.
Husserl underlines that this axiomatic foundation “is called on to participate in the ultimate grounding even of geometrical knowledge,” showing how Descartes subordinates even mathematics to this model of first philosophy.
He explicitly rejects letting this ideal govern his own project: “None of that shall determine our thinking,” distancing transcendental phenomenology from the Cartesian geometrical model of science.

Source Quotes

That would mean presupposing a whole logic as a theory of science; whereas logic must be included among the sciences overthrown in overthrowing all science. Descartes himself presupposed an ideal of science, the ideal approximated by geometry and mathematical natural science. As a fateful / prejudice this ideal determines philosophies for centuries and hiddenly determines the Meditations themselves.

Descartes himself presupposed an ideal of science, the ideal approximated by geometry and mathematical natural science. As a fateful / prejudice this ideal determines philosophies for centuries and hiddenly determines the Meditations themselves. Obviously it was, for Descartes, a truism from the start that the all-embracing science must have the form of a deductive system, in which the whole structure rests, ordine geometrico, on an axiomatic foundation that grounds the deduction absolutely.

As a fateful / prejudice this ideal determines philosophies for centuries and hiddenly determines the Meditations themselves. Obviously it was, for Descartes, a truism from the start that the all-embracing science must have the form of a deductive system, in which the whole structure rests, ordine geometrico, on an axiomatic foundation that grounds the deduction absolutely. For him a role similar to that of geometrical axioms in geometry is played in the all-embracing science by the axiom of the ego’s absolute certainty of himself, along with the axiomatic principles innate in the ego — only this axiomatic foundation lies even deeper than that of geometry and is called on to participate in the ultimate grounding even of geometrical knowledge.1 None of that shall determine our thinking.

Obviously it was, for Descartes, a truism from the start that the all-embracing science must have the form of a deductive system, in which the whole structure rests, ordine geometrico, on an axiomatic foundation that grounds the deduction absolutely. For him a role similar to that of geometrical axioms in geometry is played in the all-embracing science by the axiom of the ego’s absolute certainty of himself, along with the axiomatic principles innate in the ego — only this axiomatic foundation lies even deeper than that of geometry and is called on to participate in the ultimate grounding even of geometrical knowledge.1 None of that shall determine our thinking. As beginning philosophers we do not as yet accept any normative ideal of science; and only so far as we produce one newly for ourselves can we ever have such an ideal.

Key Concepts

Descartes himself presupposed an ideal of science, the ideal approximated by geometry and mathematical natural science.
As a fateful / prejudice this ideal determines philosophies for centuries and hiddenly determines the Meditations themselves.
Obviously it was, for Descartes, a truism from the start that the all-embracing science must have the form of a deductive system, in which the whole structure rests, ordine geometrico, on an axiomatic foundation that grounds the deduction absolutely.
For him a role similar to that of geometrical axioms in geometry is played in the all-embracing science by the axiom of the ego’s absolute certainty of himself, along with the axiomatic principles innate in the ego — only this axiomatic foundation lies even deeper than that of geometry and is called on to participate in the ultimate grounding even of geometrical knowledge.
None of that shall determine our thinking.

Context

Middle of §3, where Husserl critically examines Descartes’ implicit ideal of science, characterizing it as a prejudicial geometrical-deductive model and explicitly disavowing its normative authority for his own transcendental phenomenology.