In the horizontal aspect, human existence is the "social existence" within the space dimension and is restrained by various social relations in reality.

在横的层面上，人在空间维度内的存在是一种“社会”性的存在，又要受到种种现实社会关系的制约。

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Navy researchers admitted that human test subjects would be "more satisfactory than animals, " but they worried about the public-relations aspect of using people, so all were turned down.

WSJ: Mars One and the Scientific Embrace of Suffering