Probability and Propensities

Retrospective reflections are provided on the papers “Why Propensities Cannot Be Probabilities,” “Some Considerations on Conditional Chances,” and “Probability Theory and Its Models” by Paul Humphreys. A discussion of whether probability theory is a mathematical or an empirical theory is provided and the point made that mathematical theories are not revised but replaced when used as models of empirical phenomena. Probability theory qua formal theory has a mathematical interpretation but any empirical interpretation, contra Quine, is completely detachable. A replacement for Quine’s web metaphor is suggested. The author assesses Donald Gillies’ response to Humphreys’ Paradox, and reasons not to abandon the single case propensity interpretation of probabilities are given. Responses to the paradox by Mauricio Suárez, Isabelle Drouet, Leslie Ballentine, and David Miller are discussed, and an argument given that the temporal evolution approach is primary for absolute propensities.

The Propensity Interpretation

The propensity interpretation of probability was introduced by Popper in 1957, and the chapter begins with a discussion of Popper’s initial account of propensities and a comparison with Peirce’s related ideas. The original propensity interpretation had a number of strands, some of which could be accepted while others were rejected. This meant that the propensity interpretation could be, and was, developed in different ways by different philosophers of science. One point at issue was whether propensities were objective probabilities of single events. This led to a distinction between (i) single-case propensity theories, and (ii) long-run propensity theories. Another problem concerned the relation between propensities and causes – if propensities had a causal import, because of what is known as the Humphreys’ paradox they might not satisfy the standard axioms of probability. The chapter concludes by discussing how propensities might be connected to observed frequencies via the theory of statistical testing.

Probability in Biology

I examine the concept of “fitness” in the philosophy of evolutionary biology to show how discussions of probability in biology can go wrong, and right. Many of the critiques of the propensity interpretation of fitness have focused on the mathematical aspects of fitness; re-focusing on several aspects of the propensity interpretation of probability more generally can help to address these concerns. I conclude with some general lessons for thinking about probability in biology. The propensity interpretation of fitness, properly understood, solves the explanatory circularity problem and the mismatch problem, andalso withstands many other problems. Fitness is the propensity for organisms to survive and reproduce in particular environments and in particular populations. Fitness values can be described in terms of distributions of propensities and can be modeled for any number of generations using computer simulations. Fitness is a causal concept. Relative fitness is what matters for natural selection.

Metode Penafsiran Ibn Qayyim dalam Tafsîr al-Qur’ân al-Hakîm

<p>This article is intended as an introduction to the work of heritage interpretation Ibn Qayyim al-Jawzîyah. As an introduction course cannot be expected to complete an exposure. But from the lilte bit of description above, at least we getting conclusion that general methods are applied in interpreting. The Koran is a <em>tah</em><em>lîlî</em> method or <em>tajzi’</em>. However, if viewed from term of the propensity interpretation it’s can be categorized as a <em>al-ma’thûr</em> interpretation despite as well as the interpretation of <em>bi al-ra’y</em>. As a work of interpretation, al-Qayyim interpretation may be not as famous as the work of other commentators, such as the interpretation of <em>al-Jâmi‘ al-Bayân</em>, <em>Tafsîr Ibn Kathîr</em>, <em>Tafsîr Jalâlayn</em> an so on. But as a work of Muslim intellectuals seem this book need to be reviewed more thoroughly.</p>