经典世界的思想配角——论杨朱

在中国思想史上,杨朱不是一个大人物。他的来历、生平、著述甚至年代都没有确切的信息。但是,这个不清晰甚至显得孤单的身影,却不时出现在不同时代、不同学派的传世文本中。这一事实使通过文献考据去探讨思想史真相的手法受到限制,同时对它相关思想意义的把握也容易流于表面化。本文据“经典世界”的观点,把杨朱看成一个从不同学派的视角中交叉呈现的思想形象。这个形象是跨文本、跨时代的,它虽有某种核心性格,但却变现不同的面相。由于其出场通常是被用来陪衬其它的思想主张,因此在历史舞台上总是扮演思想的配角。杨朱思想特征的特殊性,他在经典世界的思想光谱占有不可或缺的位置。     

Systematic angular biases in the representation of visual space

Representing spatial information is one of our most foundational abilities. Yet in the present work we find that even the simplest possible spatial tasks reveal surprising, systematic misrepresentations of space—such as biases wherein objects are perceived and remembered as being nearer to the centers of their surrounding quadrants. We employed both a placement task (in which observers see two differently sized shapes, one of which has a dot in it, and then must place a second dot in the other shape so that their relative locations are equated) and a matching task (in which observers see two dots, each inside a separate shape, and must simply report whether their relative locations are matched). Some of the resulting biases were shape specific. For example, when dots appeared in a triangle during the placement task, the dots placed by observers were biased away from certain parts of the symmetry axes. But other systematic biases were not shape specific, and seemed instead to reflect differences in the grain of resolution for different regions of space. For example, with both a circle and even a shapeless configuration (with only a central landmark) in the matching task, observers were better at discriminating angular differences (when a dot changed positions around the circle, as opposed to inward/outward changes) in cardinal versus oblique sectors. These data reveal a powerful angular spatial bias, and highlight how the resolution of spatial representation differs for different regions and dimensions of space itself.