A considerable challenge confronts, any developing neuron. Before it can establish a functional and specific connection, it must extend an axon over tens and sometimes hundreds of microns through a complex and mutable environment to reach one out of many possible destinations. The field of axonal guidance concerns the control of this navigation process. To satisfactorily identify the cell interactions and molecular mechanisms that mediate axonal guidance, it is essential to first identify the pertinent cell populations. Embryonic surgeries have provided (...) solid information on which tissues are critical and which are irrelevant to the navigation of motor axons within the chick embryo. The gross anatomical nerve pattern is established as axons respond to both positive (path) and negative (barrier) tissue environments. Analysis of the interactions of motoneurons with these tissues reveals that several cellular interactions – chemotaxis, substratum preference, and perhaps contact paralysis – are important to the common patterns of motor axon advance. Axons simultaneously interact with population‐specific cues that have begun to be identified on the tissue level. (shrink)

This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain (...) in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant. (shrink)

In this study, Daniel W. Graham addresses two major problems in interpreting Aristotle. First, should we reconcile the apparent inconsistencies of the corpus by assuming an underlying unity of doctrine, or by positing a sequence of developing ideas? Secondly,what is the relation between the so-called logical works on the one hand and the physical-metaphysical treatises on the other? Although the problems appear to be unrelated, Graham finds that the key to the first lies in the second, and in doing so (...) provides the first major alternative to theunitarian approach since Jaeger's pioneering developmental study of 1923. (shrink)

AT PHAEDO 96A-C Plato portrays Socrates as describing his past study of "the kind of wisdom known as περὶ φυσέως ἱστορία." At 96c-97b, Socrates says that this study led him to realize that he had an inadequate understanding of certain basic concepts which it involved. In consequence, he says at 97b, he abandoned this method and turned to a method of his own. But at this point in the dialogue, instead of proceeding immediately to describe his method, Plato has him (...) interjecting a complaint concerning Anaxagoras and his view that everything should be explained in terms of Mind. His complaint is that Mind would order things in the best possible way and that, therefore, an account of things in terms of Mind would amount to showing that they are ordered in the best possible way. But Anaxagoras did not show this and, instead, offered other kinds of explanations of the various phenomena. Socrates is not just criticizing Anaxagoras here for not doing what he set out to do; he makes it clear, for example at 99b-c, that he believes that the best kind of explanation of the phenomena would be to show that they are ordered in the best possible way. But he was unable to discover an explanation of this kind, either for himself or from others, and so turned to a method which he calls "second best". The actual description of this method is contained in two passages, 99e5-100a7 and 101d5-e1. Between these passages, Socrates invokes the doctrine of Forms and, in particular, the formula. (shrink)

Spanning pivotal years in the historic democratization of South Africa, this analysis provides a trenchant reflection of higher education in transition. Penned by one of South Africa’s foremost philosophers of education, the critique grapples with very real concerns in higher education policymaking and practice, including stakeholder politics, institutional cultures, and curriculum transformation and interrogation of the function of higher education institutions in modern societies. Exposing the tensions between egalitarian principles and the nature of higher knowledge, the essays raise questions to (...) which there are no simple answers. With characteristic rigor, the analysis looks into the assumptions underlying much of the thinking about these questions and concludes that a failure to sharpen thinking around higher education is a failure to recognize the epistemic value of academic practice in a developing democracy. (shrink)

L'A. soutient, contre Germain Grisez, Joseph Boyle, John Finnis et William May, que le contrôle naturel des naissances pratiqué avec une intention mauvaise n'est pas contraception. Il montre que les auteurs identifient de façon incorrecte la fin prochaine de la contraception comme choix qu'il n'y ait pas d'enfant, alors que la fin prochaine véritable est d'empêcher un enfant de venir au monde . Ainsi donc, puisque en NFP un couple ne cherche pas à empêcher la venue au monde d'un enfant, (...) NFP n'implique pas d'action contraceptive. L'A. soutient aussi qu'identifier la fin prochaine comme choix qu'il n'y ait pas d'enfant ne spécifie pas de façon adéquate une classe homogène d'actes objectifs, bien que cela spécifie une classe homogène d'actes moraux. (shrink)

In Rethinking the Philosophy of Religion Today, this paper would like to advance the atheist solution to the problem of evil that has occasionally in the past been suggested by philosophers, but has largely been neglected in the Philosophy of Religion. In discussing this solution, the paper focuses on the reasons upon which philosophers regard the giving up of one or more of the attributes of God in theism to be an adequate solution to the problem of evil. Concerning the (...) more negative of these reasons, it shows that the latter revolves around the argument of the logical inconsistency of the theistic theory. Concerning the more positiveof these reasons, the focus is on the efforts of philosophers that have been following the suggestions of David Hume and that have started to experiment with solutions wherein at least one of the attributes of God is given up. The paper closes by showing that there exist an even more fundamental reason upon which it can be claimed that the problem of evil can be solved along this way without serious implications for a belief in God. (shrink)

William Cunningham was a prominent British economist and economic historian. In this book, which was first published in 1917, Cunningham provides a concise guide to various aspects of political philosophy, with a particular focus on British political institutions. Appendices are included and textual notes are incorporated throughout. This book will be of value to anyone with an interest in political philosophy and the nature of governance.