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Philosophical Works · Chapter

XXVIII explained

This chapter argues that in natural philosophy we should not seek final causes (the ends God or nature intended) but rather efficient causes, because we cannot presume to know God's purposes.

What happens

This chapter argues that in natural philosophy we should not seek final causes (the ends God or nature intended) but rather efficient causes, because we cannot presume to know God's purposes. Instead, we should use the natural light God gave us to investigate the effects we perceive, trusting that light only as long as it is not contradicted by divine revelation.

Themes in this chapter

  • Reason and Method

    The chapter emphasizes using the natural light of reason to investigate efficient causes, a key aspect of Descartes' method.

  • Existence of God

    God is presented as the efficient cause of all things, and the natural light is described as planted in us by God.

Characters to notice

  • Narrator

    The voice presenting the argument against seeking final causes and in favor of efficient causes.

  • God

    Referenced as the efficient cause of all things and the source of the natural light, whose counsels we cannot share.

Key passages

  • we will not seek reasons of natural things from the end which God or nature proposed to themselves in their creation (i.e., final causes), for we ought not to presume so far as to think that we are sharers in the counsels of Deity

    We should not try to explain natural phenomena by appealing to the purposes God or nature had in creating them, because we cannot assume we know God's intentions.

    Descartes explicitly rejects final causes in natural philosophy.

  • considering him as the efficient cause of all things, let us endeavour to discover by the natural light which he has planted in us, applied to those of his attributes of which he has been willing we should have some knowledge, what must be concluded regarding those effects we perceive by our senses

    Instead, we should treat God as the efficient cause of everything and use the innate reason he gave us—applied to what he has revealed about himself—to draw conclusions about the things we observe.

    This outlines Descartes' positive method: using reason (natural light) to study efficient causes.