Husserl’s Phenomenological Reduction


Husserl’s Phenomenological Reduction is central to his philosophy. In this article, I answer the questions:

  • What Is It?
  • Why Does Husserl Believe It To Be Necessary?

The concept of the phenomenological reduction can be argued to have a long philosophical pedigree via the epoché (εποχη) of the Greeks and importantly via the program of Descartes. Husserl entitles his work “Cartesian Meditations”, because essentially his project is to revive and renovate Descartes’ foundationalism.

Among the Greeks, Pyrrho is described by Diogenes Laertius as using the term epoché to mean “introducing the form [of philosophy] consisting of non-cognition and suspension of judgment.”

Descartes sought to use a method of radical disbelief to establish secure foundations for knowledge; the attempt being to find indubitable facts that in turn could support a natural science of the world. Husserl moves on however, as described by Kuspit: “Husserl begins where Descartes ends: with consciousness suspended without its own sanctions for objectivity, purified and thereby certain. The essence of this suspension is epoché; and the beginning of epoché is, as, Husserl makes clear in Ideas, the predication of the possibility ‘to doubt everything’ ”

Husserl’s aim is to arrive at apodictic certainty. This is a level of certitude beyond what one might routinely term certainty; it is possible to be certain in a particular belief and yet be mistaken. Apodictic certainty is superior to this because the concept included the idea that the contradictory is unimaginable. Husserl appears to believe himself to be following Descartes in equating absolute apodictic certainty with indubitability.

The process to be followed in arriving at such apodictic certainty is the phenomenological reduction, which seeks to eliminate all that is not directly given. This is surely necessary to such a process, though being necessary does not make it necessarily possible. We can see why the reduction is necessary by considering with Quine the gross asymmetry between a “meager input and torrential output”, by which he means the significant amount of internal encrustation that appears to be added to the two dimensional visual field.

That field is all we can observe using the visual sense, and yet we seem to be able to produce a vast array of additional ‘commentary’ including statements about the third dimension and the likely history. Surely we can agree with Husserl that the attempt to eliminate these additions, which may be artifacts of our consciousness, is necessary to finding any apodictic truth. In Husserl’s own terms, “It is necessary to say that the reduction has apodictic significance, since it shows apodictically that the being of the transcendental Ego is antecedent to the being of the world.” This means that because some element of the Ego forms part of the phenomenological residuum that remains, after the reduction has taken the world ‘out of play’, it is prior to the world since that is in its entirety no longer in consideration.

We can picture the reduction in its visual incarnation as being like an attempt to see only colors and perhaps shapes without the immediately attendant and apparently automatic resolution by, as we know now, our visual cortices into objects at range with volume and a slew of attendant ‘assumptions’. It is immediately clear that there is a serious question as to whether this is actually possible or whether it can only be considered as a thought experiment.

The reduction achieves the remarkable feat of being simultaneously banally obvious and deeply shocking. We are to take what we see as it is and not as something else. This is obvious in one sense because surely any other course of action would involve the smuggling in of potentially unwarranted non-perceived items. It is shocking once we realize the vast amount of what we commonly take for granted is thus eliminated.

One forerunner of the frequently used slogan for the reduction as being equivalent to ‘putting the world in brackets’ can be seen when Husserl writes of “this universal depriving of acceptance” as being equivalent to the “‘parenthesizing’ of the Objective world”. This is a substantial departure from the line taken by Descartes. It is possible to accept at face value Descartes’ claim that he will resolve to doubt everything. Alternatively, it can be viewed more as a method than a fact; it is after all, unclear to what extent if any we are in control of our beliefs. Schmitt refers back to Husserls’ background to explain this bracketing terminology: “Husserl draws his metaphor from mathematics where we place an expression in brackets and put a + or – sign in front of it. By thus bracketing the objective world we “give it a different value”. Schmitt could continue that by use of brackets, we could also multiply an entire series of combined terms by zero.

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Hume famously speaks of the skeptical doubts engendered in him by philosophical study as being dispelled by ordinary life including billiards, wine and friends. So both of those philosophers may be regarded, along with other members of their pre-Husserlian traditions, as being oscillatory in their belief status. Husserl on the other hand maintains a stable agnosticism; he seeks to remove the world from consideration rather than doubt it in order to cease doubting it. There seems much less scope to claim that Husserl is not able to restrict his focus in this way than to argue that Descartes does not really exercise a universal doubt.

Perhaps another useful approach to the reduction is to see it as an attempt to find a precise demarcation of the contours of the subjective and isolate the boundary thereof with the objective. Only in this way can one hope to achieve a scientific view by understanding what is true for everyone and what our consciousness, and theirs, has added, this latter being for Husserl suspect and to be removed from consideration.

Two significant elements of Husserl as an individual can be introduced that may provide useful background to his philosophy and the reduction which is at its heart as the first methodological principle. Firstly, he made a decision as a mature adult to convert to Christianity. Secondly, he had a strong scientific background, studying astronomy and mathematics at university and later wrestling with the decision as to whether to continue in mathematics or devote himself to philosophy.

This first factor can suggest a desire to attack skepticism and the corrosive effects that it could have on human behavior. For Husserl, it seems that skepticism represented an actual quasi-moral danger rather than an interesting intellectual exercise. He also compared the decision to undergo or undertake the reduction as akin to a religious upheaval, which can indicate its difficulty, its importance, its consequences and perhaps a certain evangelical inspiration on its behalf.

The second factor can suggest that Husserl would have liked to take a line redolent of Spinoza, starting with the reduction as a (producer of a) fundamental axiom and proceeding thence in impeccable Euclidian format to all the knowledge of natural science. There is a link here back to the reduction. As D Moran puts it, “nothing factual need exist at all for the geometer who is concerned only with essential possibilities”; likewise the phenomenologist does not need the world.

A D Smith claims that Husserl distinguishes the epoché from the transcendental reduction; with the former being the aim of the latter. In the epoché, we bracket the world, while in the reduction, we restrict our attention to that which is phenomenologically given. Clearly the epoché is closely linked to the reduction and necessary to it on this reading.

One common understanding of the process of the reduction relies on Husserl’s concept of noema, in which he revived a Greek term meaning the content of an intentional act, and wherein intentional is used in its technical sense to mean referring to or pointing at. A noema refers in some way to an object in the world. We could then see the reduction as being a dissociation of the intentional act or thought from its noema; it is important to note that this dissociation is not the same as one that would sever a noema from an external object. Hintikka makes the contrary point however, that we cannot imagine a relation without having an idea of both of its relata, in the way that drawing a line on a map from London to another place [x] is a process which makes no sense and cannot be begun unless we know the name and location of [x]. Again, this argument can be seen as part of a line-drawing exercise being conducted by Husserl, albeit an exercise of some importance, since a correct placement of the boundary will result in a method of approaching objective truth, if successful.

One of Husserl’s own slogans, which is relevant in the context of trying to understand the reduction, was ‘to the things themselves’. This however can be highly misleading and needs to be appreciated with a substantial measure of Kantian transcendent sensibility. It is worth noting that Husserl saw attaining a ‘transcendent’ perspective as central to his endeavor; this very Kantian term should serve to suggest that the things in question may not be what they seem and in fact may not be there at all. A D Smith believes that Husserl’s view is that the transcendental perspective is one in which we understand fully the constituting role consciousness plays in creating our perceptions and in fact the world. Kant holds that the noumenal world of things in themselves is forever and in toto inaccessible to us, yet he still claims they exist. For Kant, we can only have access to the phenomenal world, that of how things seem to us: this is what Husserl seeks to examine, to this he calls our attention in the slogan and for this reason he is the founder of phenomenology.

See Also:

Schopenhauer Claims Objects Are Representations — What Does This Mean And Can It Be Defended

Merleau Ponty’s Phenomenology: What Is It And How Cogent Is It?

What Is “Theory Of Mind?”

Schopenhauer Claims Objects Are Representations — What Does This Mean And Can It Be Defended


  • Richard Bett, ‘What Did Pyrrho Think about “The Nature of the Divine and the Good”?’ Phronesis, Vol. 39, No. 3 (1994), pp. 303-337
  • Donald B. Kuspit, ‘Epoché and Fable in Descartes’, Philosophy and Phenomenological Research, Vol. 25, No. 1 (Sep., 1964), pp. 30-51
  • W V Quine, ‘Naturalized Epistemology’, in Ontological Relativity and Other Essays, New York, Columbia University Press, 1969
  • E Husserl, ‘Cartesian Meditations’, Kluwer Academic Publishers, 1999, p. 18
  • E Husserl, ‘Cartesian Meditations’, Kluwer Academic Publishers, 1999, p. 20
  • R Schmitt, ‘Husserl’s Transcendental-Phenomenological Reduction’, Philosophy and Phenomenological Research, Vol. 20, No. 2 (Dec., 1959), pp. 238-245
  • D Hume, ‘Treatise of Human Nature’,, Volume One, p. 457
  • B Smith and D W Smith, eds, ‘The Cambridge Companion to Husserl’, Introduction
  • D Moran, ‘Introduction to Phenomenology’, Routledge 2000, p. 135
  • A D Smith, ‘Husserl and the Cartesian Meditations, Routledge 2003, p. 27
  • B Smith and D W Smith, eds, ‘The Cambridge Companion to Husserl’, Cambridge University Press, 1999, Chapter Two