Blaise Pascal’s Philosophy of Nature

By Douglas Groothuis, PhD, Distinguished Professor, Cornerstone University

The Frenchman, Blaise Pascal (1623-62), is known for many things—inventing the first working calculator (the Pascaline), for his wager on God argument, and for his statement that “the heart has reasons that reason knows nothing of.” Since he is among the most quotable philosophers, we may have seen a piquant from him scattered in various books and articles. Sadly, his religious and philosophical views are often unknown, since they are misinterpreted and even caricatured, particularly this brilliant wager argument.[1]

However, Pascal is usually remembered as a scientist and mathematician. Some may know that he devised an empirical experiment to demonstrate that nature, popular and received opinion to the contrary, did not “abhor a vacuum” (although we still hear that). By considering this experiment and his writings on the philosophy of science, we can discern his pathbreaking philosophy of science and how this sheds light on our scientific and religious questions.

Overcoming Prejudice About Nature

Pascal’s greatest scientific accomplishment was his work on the existence of the vacuum.[2] These reflections were also pivotal in the development of an empirically based scientific method. Although it is assumed today that scientific procedures should be grounded in repeatable empirical observation as much as possible, this was not the received view in Pascal’s day. Cosmology was dominated by two very different and antithetical views, both of which, nevertheless, were united in their denial of the existence of a vacuum. The Aristotelian and later medieval notion claimed that nature was a hierarchical plenum or continuum devoid of any gaps. This was sometimes called the great chain of being. In this qualitatively oriented cosmology, substances were thought to possess esoteric qualities or forms: heaviness makes lead fall faster than a feather, whose defining quality is lightness. Wood burns because it has the form of being combustible, and so on.

A second reason invoked in favor of the maxim that “nature abhors a vacuum” was the newer and revolutionary theory of Descartes. Instead of a qualitative concept of nature, Descartes attempted to explain matter (which he defined as extension) in strictly quantitative terms. Mathematics and mechanics could explain physical phenomena in all its forms without appeal to qualitative terms. This view would simplify and unify the sciences according to physical laws deductively derived according to a priori principles apart from experimentation. Matter was interchangeable with the geometrical points, or space, in which it is located. Matter, understood as extension, is identical with physical space. Therefore, the idea of empty space (or a vacuum) is a contradiction in terms within the Cartesian system.

Enter the Vacuum

Pascal, however, was not convinced by either argument against the vacuum. Pascal clearly distinguished between the authority delivered by the Christian religion and the need for independent, empirical observation in matters not directly addressed in sacred writ or in church tradition. In October of 1646, Pascal repeated the barometric experiments of Evangelista Torricelli (1608–1647), a disciple of Galileo, which had caused quite a stir among natural philosophers. By inverting a long glass tube filled with mercury in a bowl of mercury, he noticed that the mercury in the tube dropped down until it was about 76 centimeters above the level in the bowl. The purpose of the experiment was to confirm Galileo’s suspicions about the role of the atmosphere in limiting the height to which a pump could lift water. It also suggested that when the mercury dropped, the space remaining at the end of the tube must be a vacuum. This, of course, struck an experimental blow against the vacuum deniers.

In 1647, Pascal published the results of his barometric experiments in New Experiments Concerning the Vacuum. After a series of detailed experiments, Pascal maintained that any appeal to some esoteric matter (instead of a true vacuum) was unsubstantiated. After explaining his various experiments, he concluded, “After having demonstrated that none of the substances perceived by our senses and known by us fills this apparently empty space, I shall think, until I am shown the existence of a substance filling it, that it is really empty and void of all matter.”[3]

Pascal pointed out that a conformity of all the facts to a hypothesis serves only to make the hypothesis probable; a single contrary phenomenon can prove the hypothesis false. This approach has affinities with Karl Popper’s falsification theory of science. Pascal’s thinking on the role of theory and evidence with respect to the vacuum is still greatly admired by philosophers of science as an accomplished statement of correct scientific methodology.

Pascal rejected an overly personalized or anthropomorphic notion of nature in favor of a more mathematical and empirically-based perspective. However, he believed that a personal and sovereign God was the author and Lord of nature. Thus, his idea was not secular.

While Pascal challenged and overturned a concept of nature that gave it quasi-emotional qualities (nature abhors a vacuum) in favor of empirically derived understanding involving quantities and principles, he did not deny teleology or final causes and thus contribute to a reductionistic account of God’s natural world. He writes: “There are perfections in nature to show that she is the image of God and imperfections to show that she is no more than his image.”[4]

Since God is a purposeful being, and if creation is in his image, then it, too, must be purposeful. This should be remembered even when Pascal expatiates on the smallness of humans in a complex and often unfathomable world.[5] Further, Pascal believed that human beings are endowed with purpose by their Creator and that they can find eternal purpose through their Savior, Jesus Christ.[6]

Pascal deemed the discovery of objective truth to be the best intention of scientific study and of all study: “Whatever the weight of antiquity, truth should always have the advantage, even when newly discovered, since it is always older than every opinion men have held about it, and only ignorance of its nature could [cause one to] imagine it began to be at the time it began to be known.”

Authority, reason, and observation all had distinctive, irreducible, and (ultimately) harmonious roles in the acquiring of objective scientific knowledge. In Pensées, Pascal later applied this basic insight regarding various ways of knowing to his analysis of religious rationality and authority. In the case of Christianity, he argues that revelation, reason, and experience all contribute in different ways to justifying religious belief.[7] 

After his dramatic “second conversion,” Pascal did not pursue mathematics or science as intensely as previously, but he did not renounce them. Part of the reason for this may have been increasingly poor health, along with his desire to produce his Apology for the Christian Religion. Moreover, he seemed to associate his former successes in mathematics and science with his struggle with pride. Nevertheless, in 1658 during a sleepless night due to a terrible toothache, he turned his attention to a mathematical puzzle called the cycloid, which concerns the curve made by a point on the circumference of a circle traveling over a flat surface. Pascal published the piece and issued a challenge with a monetary reward to others to outdo his calculations.

Pascal, Science, and the Secular

Pascal’s contributions to experimental science and the philosophy of science put the lie to the idea that science must be secular and materialistic to be legitimate. Pascal realized that while Scripture spoke to salvation, ethics, the afterlife, and God’s as Creator, it left much open for empirical discovery of the contingencies of God’s world of discovery.[8] For this, and much else, we are in his debt.[9]

[1] See Douglas Groothuis, “Wagering a Life on God,” Beyond the Wager: the Christian Brilliance of Blaise Pascal (InterVarsity-Academic, 2024).

[2] This and the next section draw from Groothuis, “Scientist and Philosopher of Science.”

[3] Blaise Pascal, “New Experiments Concerning the Vacuum,” trans. Richard Scofield, in Pascal, Great Books of the Western World 33 (Chicago: Encyclopedia Britannica, 1952), 364.

[4] Pascal, Blaise. Pensées (Penguin Classics) (p. 298). Penguin Books Ltd. Kindle Edition.

[5]  Pascal, Pensées, Kindle, 58-65. John Frame discusses this fragment as an example of general revelation in Nature’s Case for God: A Brief Biblical Argument (Bellingham, WA: Lexham, 2018), 21-27.

[6] See Groothuis, “The Excellence of Christ,” Beyond the Wager.

[7] See Groothuis, Beyond the Wager.

[8] Stephen C. Meyer, Return of the God Hypothesis (HarperOne, 2021), 34-35, states that the idea of the contingency of nature helped lead to the scientific revolution, since the idea demanded a hands-on, empirically-based approach to science. He is right, but does not mention Pascal in this.

[9] See Graham Tomlin, Blaise Pascal: The Man Who Made the Modern World (Hodder Faith, 2025).