I tested the hypothesis that, in infant-mother-sibling interactions, infants with older siblings aged 11 to 24 months produce deictic gestures when they are proximal to, or engaging in joint attention with, their mothers more frequently than same-aged infants without siblings. Fifteen infant-mother dyads and 10 infant-mother-sibling triads were individually observed for 15 minutes in a playroom full of toys. Infants involved in infant-mother-sibling interactions produced more deictic gestures when they were proximal to their mothers than infants in infant-mother interactions. Further, (...) infants involved in infant-mother-sibling interactions accompanied their gestures with vocalizations at a higher rate than infants in infant-mother interactions. This result suggests that infants with older siblings monitor their mothers more carefully in interactions in which their sibling is also present, and that they produce deictic gestures in order to effectively elicit joint action with their mothers. (shrink)

In this paper, we generalize a result of Brown and Simpson [1] to prove that RCA0+Π0∞-BCT is conservative over RCA0 with respect to the set of formulae in the form ∃!Xφ, where φ is arithmetical. We also consider the conservation of Π00∞-BCT over Σb1-NIA+∇b1-CA.

This article provides the first English translation of Tanabe’s early essay, “The Limit of Logicism in Epistemology: A Critique of the Marburg and Freiburg Schools”. The key notion that the young Tanabe seeks to define in relation to his detailed analyses of contemporary Neo-Kantian epistemology is the notion of “pure experience” presented in Nishida’s philosophy. The general theory of epistemology shared among the thinkers from these two prominent schools of philosophy in early 20 th century Germany aimed to eliminate the (...) empirical residues in Kant’s theory of knowledge while opposing naïve empiricism and the uncritical methodology of positive science. Their “logicistic” approach, according to Tanabe, seems to contradict Nishida’s notion of pure experience, for it cannot allow any vestige of empiricism in its systematic framework, which is specifically designed to ground scientific knowledge. Yet given that the Neo-Kantian configuration of epistemology does not create the object of knowledge, it must face sensation or representational content as its limiting instance. Thus, to ground a Neo-Kantian theory of knowledge while taking account of this limit of logicism involves explaining their understanding of the unity of subject and object in human knowing. For this, Tanabe argues, recourse to Nishida’s notion of pure experience is indispensable. (shrink)

One most common problem in reinforcement learning systems (e.g. Q-learning) is to reduce the number of trials to converge to an optimal policy. As one of the solution to the problem, k-certainty exploration method was proposed. Miyazaki reported that this method could determine an optimal policy faster than Q-learning in Markov decision processes (MDPs). This method is very efficient learning method. But, we propose an improvement plan that makes this method more efficient. In k-certainty exploration method, in case there is (...) no k-uncertainty rule (rules which aren’t selected more than k times) in current state, an agent sometimes walks randomly until it finds a state where it can select a k-uncertainty rule. We think that this behavior is not efficient. To reduce this useless behavior, we propose combining k-certainty exploration method with Dynamic programming (DP). Miyazaki’s system uses DP after all rules are executed at least k times. But, our method uses k-certainty exploration method along with DP during learning. Our method, takes two pattern actions. In case an agent can select k-uncertainty rules, one of these rules is selected at random as k-certainty exploration method. In another case there is no k-uncertainty rule, behavior of agent is different from the behavior of k-certainty exploration method. In that case, our method uses DP to compute an optimal policy for moving from a current state to a state in which some k-uncertainty rules remain. The model for DP is constructed by using only known states. The outline will be described below. First, an agent makes a map constructed by using only known states. In the map, goals are states in which there are k-uncertainty rules and arbitrary state values are set in these states. Point to which attention should be paid is that the map is not given from outside. It is made from only experience. Next, each state values of states in which there are only k-certainty rules in the map are computed by DP (we used Policy Iteration). Finally, an agent continues to select greedy action until it arrives at a state in which it can select a k-uncertainty rule. By this improvement, we expect it can determine an optimal policy faster than k-certainty exploration method. And we have verified that our exploration method can determine an optimal policy faster than k-certainty exploration method by computer simulation. (shrink)

In this paper, we investigate the logical strength of completeness theorems for intuitionistic logic along the program of reverse mathematics. Among others we show that is equivalent over to the strong completeness theorem for intuitionistic logic: any countable theory of intuitionistic predicate logic can be characterized by a single Kripke model.

Reading “The Tale of Genji”: Sources from the First Millennium. Edited by Thomas Harper and Haruo Shirane. New York: Columbia University Press, 2015. Pp. xx + 610. $65.

Productive sets are sets which are “effectively non recursively enumerable”. In the same spirit, we introduce a notion of “effectively nonrecursive sets” and prove an effective version of Post's theorem. We also show that a set is recursively enumerable and effectively nonrecursive in our sense if and only if it is effectively nonrecursive in the sense of Odifreddi [1].

According to the “truthmaker maximalism”, every true contingent proposition is made true by something in the world, called its truthmaker. Although at first sight the maximalism seems to be a natural position, it has serious difficulties, especially concerning negative truths. In view of this, many truthmaker theorists adopt some non-maximalist position. It is not clear, however, whether these non-maximalists are justified, since existing reasons to justify the non-maximalism are not good enough. In this paper, then, I shall propose a new (...) reason for the non-maximalism, which consists in the observation that the maximalism cannot acknowledge the widely accepted view that certain inferences involving logical constants are valid in the properly logical sense. (shrink)

The Manifestation Requirement, advanced by Dummett in his critique of semantic realism, has been criticized for being behavioristic, and the responses have been made that the critics are mistaken. However, the dispute has failed to exhibit the point of the Requirement. In this paper, I shall argue (1) that, in the light of Anscombe's theory of practical knowledge, knowledge of linguistic meaning is to be seen as the knowledge-how that forms the basis of the practical knowledge that an agent has (...) of his own intentional actions, (2) that such knowledge of linguistic meaning is to be based on mutual agreements in a community, and (3) that the Manifestation Requirement is a condition for the possibility of such mutual agreements. As a result, the Manifestation Requirement finds its basis on the idea that language and linguistic acts are tools that we use while continually improving them. (shrink)

Japanese philosopher Miki Kiyoshi 三木清 wrote an important text on translation entitled “Disregarded Translations”. Among all Kyoto School thinkers, Miki was probably the most prolific writer. His interests spanned various intellectual topics such as philosophy, literature, religion, politics, and journalism. This paper offers a brief introduction to Miki’s conception of translation as well as, for the first time, an English translation of his text. “Disregarded Translations” deals with Japanese scholars’ propensity to revere Western philosophical texts in their original forms, while (...) ignoring the outstanding wealth of insight that their translations can provide in their own language. (shrink)

Is there anything that is given immediately? This question seems to be of crucial importance for Phenomenology, a field perhaps known most principally for its attempt to return directly to the “things themselves.” The seeming simplicity of the idea is appealing: after all, where better for us to start in any philosophical investigation than with things as they appear to us in their most pure or “immediate” state? When put in its historical context as well, Husserl’s phenomenological project could even (...) be interpreted as a breath of fresh air in the midst of the environment of early 20th century philosophy in comparison with the seemingly constructive philosophy of its Neo-Kantian contemporaries. Indeed, rather than starting with a merely systematic account of our cognition and reality, is it not better for us to first return to the world just as it is given to us in perception or intuition in order to have a more faithful account of these issues? (shrink)

私たちにとって歴史とは何か。改めて歴史意識を取り戻すため、橋川文三を今、とらえ、読むための入門書。.