The Epicurean Canon in La Mettrie

The following is part of a book review of Histoire Naturelle de l’Ame by Julien Offray de La Mettrie.

In his Letter to Herodotus, Epicurus establishes the criteria of truth. This criteria are the faculties that nature gave us as a contact with reality: the anticipations (which form as we encounter and memorize sense objects), the five senses, and the pleasure-pain faculty.

It is essential that the first mental image associated with each word should be regarded, and that there should be no need of explanation, if we are really to have a standard to which to refer a problem of investigation or reflection or a mental inference. And besides we must keep all our investigations in accord with our sensations, and in particular with the immediate apprehensions whether of the mind or of any one of the instruments of judgment, and likewise in accord with the feelings existing in us, in order that we may have indications whereby we may judge both the problem of sense perception and the unseen. – Epicurus, in his Epistle to Herodotus

In this essay I will evaluate passages from Natural History of the Soul that discuss how the canon is to be used. We will once again see that his system and method are essentially Epicurean.

But, first of all, why is this subject important? In the first pages of the book, La Mettrie explains that not knowing the nature of the soul makes us submit to ignorance and faith, and that one can’t conceive the soul as abstraction, separate from the body. Body and soul were made at once together; to know the properties of the soul one must research those of the body, of which the soul is the animating principle. Since all properties that we observe suppose a subject they’re based on, idealists posit the soul exists by itself without the body, that it is unnatural or immaterial. In setting up a doctrine of unity of body and soul, La Mettrie answers to the idealists:

Yes, BUT why do you want me to imagine this subject to be of a nature absolutely distinct from the body?

The key premise of Natural History of the Soul is that the soul is physical, part of the body, and that it’s born with and dies with the body. Like Epicurus explains in his Epistle to Herodotus, the body is the passive component and the soul is the active component of the self; and furthermore, he says that there are no surer guides than the senses in our inquiry into the nature of the soul.

Reason: a Mechanism that Can Go Wrong

La Mettrie is, among other things, a defender of pleasure and highly skeptical of the value of reason. He also argues that happiness is not found in thoughts or in reason, but is born of the body.

Happiness depends on bodily causes, such as certain dispositions of the body, natural or acquired–that is, procured by the action of foreigner bodies over ours. – La Mettrie, in Histoire naturelle de l’ame, page 135-136

He argues that some people are by birth happier than others. He also argues that proud reason is a mechanism which can go wrong, and in paragraph 79 of his Système d’Epicure he speaks of how cold reason “disconcerts, freezes the imagination and makes pleasures flee“.

The Senses

It’s difficult to know to what extent La Mettrie based his Natural History of the Soul on Lucretius.

To speak the truth, the senses never fail us, except when we judge their reports with too much precipitation, for otherwise they are loyal ministers. The soul may surely count on being averted by them of pitfalls thrown its way. The senses are ever alert, and are always ready to correct each other’s errors. –  Histoire Naturelle de l’Ame, p. 69

Elsewhere he seems to concede that the senses aren’t fully reliable because perceptions can change. Sweet fruit becomes sour, even colors change with lighting. To all this, Epicurus would answer that even if we concede that the senses can err (and they do), still they are our best and only criteria that connect us with reality.

Towards the end of the book, we are raptured into a fascinating world of real-life Tarzans from European history when the author shares several stories that confirm that all ideas come from the senses. He narrates one story about a deaf man from Chartres who, upon hearing bells, started recovering his hearing. When he later started talking and was questioned by theologians, he didn’t understand the meaning of the concept of god or ideas related to the afterlife, etc. Another story had to do with a blind man who had to use touch to get an idea of things. Finally, he narrates the story of Amman, who taught the deaf to speak with touch and sight. He would have them touch their throat to feel the vibration of sound there, and read lips and use mirrors to practice using sight. (Interestingly, the It’s Okay to be Smart YouTube channel has a video on how blind people see with sound) At the closing of the book, the author says:

From all that has been said up to the present, it is easy to conclude with evidence that we don’t have a single innate idea, and that they’re all the products of the senses

He goes on to offer the formula:

No education, no ideas.
No senses, no ideas.
Less senses, less ideas.

Anticipations: a Constant Law

While La Mettrie doesn’t directly mention anticipations (the third canonic faculty), he does describe this faculty when he discusses speech and memory. I will make an attempt to offer a clear translation from the French, which is made difficult by the fact that the author uses long sentences.

The cause of memory is, in fact, mechanic–as memory itself is. It seems to depend on that which is nearby the bodily impressions of the brain, which trace ideas that follow it. The soul can not discover a trace, or an idea, without reminding the others which customarily went together. – La Mettrie, speaking of the “bodily impressions of the brain in p. 88-89 of “Natural history of the soul”

Since in order for a new movement (for instance, the beginning of a verse or a sound that hits the ears) to communicate on the field its impression to the part of the brain that is analogous to where one finds the first vestige of what one searches (that is, this other part of the brain (see note) where memory hides, or the trace of the following verses, and represents to the soul the follow-up to the first idea, or to the first words, it is necessary that new ideas be carried by a CONSTANT LAW to the same place to where the other ideas of the same nature as these were carried. – La Mettrie, speaking of the “constant law” by which memory functions in p. 89-90 of “Natural history of the soul”

(note: he uses the word moelle, which translates as “bone morrow”, but he must be referring to brian tissue or brain lobe of some sort)

Now, we know that much of La Mettrie’s writing was inspired on or based on Lucretius’ De Rerum Natura, and this passage in particular is related to the passage where Lucretius mentions neural pathways in the brain. Notice that La Mettrie also refers to ideas tracing a path inside the brain.

Notice also that this is remarkably scientific, considering when it was written. To La Mettrie, ideas are “bodily impressions” in the brain. Ideas are material: they are physical and are lodged in (or happen to) the brain. Today we know that ideas are, concretely, electric signals shared by neurons according to established connections in the nodes between them, which are formed as a result of habitual and instinctive behavior by the animal.

Furthermore–and this is another feature of the canon as it is understood by most modern Epicureans: in p. 93 La Mettrie argues that the fact that we remember or recognize ideas with or without the consent of the will is seen as proof that they are pre-rational. The anticipations are sub-conscious, and obey what La Mettrie calls an “internal cause”.

Some Conclusions

The author seems intimately familiar with many details of the Epicurean canon. It seems that much of what he wrote were commentaries on Lucretian ideas, and that he was unfamiliar with Epicurus as a direct source. His familiarity was with Lucretius, which was a popular document in the intellectual life of anti-religious intellectuals of his day.

He does not use the same words as Lucretius (or Epicurus) used. He is employing clear speech in his native language to name things that we know as anticipations, canon, dogmatism, etc. He used “système” for dogmatic systems of philosophy, and referred to anticipations functionally as they related to memory and speech.

La Mettrie regards reason and the canonic faculties similarly to how the orthodox Epicurean does. He says of reason that it’s a “mechanism which often fails”. He frequently uses the term “internal causes” here (as opposed to “external”), perhaps admitting some acknowledgement of the existence of the unconscious or subconscious mind. That he goes to such lengths to argue that these faculties are pre-rational is very interesting.​​

Next, we will be focusing on controversies against the creationists and theologians.

Further Reading:

A Concrete Self

Author: hiramcrespo

Hiram Crespo is the author of 'Tending the Epicurean Garden' (Humanist Press, 2014), 'How to Live a Good Life' (Penguin Random House, 2020), and Epicurus of Samos – His Philosophy and Life: All the principal Classical texts Compiled and Introduced by Hiram Crespo (Ukemi Audiobooks, 2020). He's the founder of, and has written for The Humanist, Eidolon, Occupy, The New Humanism, The Secular Web, Europa Laica, AteístasPR, and many other outlets.