A.I. Explanation:

Option 1: "Our existence vis-a-vis the outside world"

Explanation: This option refers to the basic elements of existence and the external environment, which the text mentions as things we have no doubt about. However, it does not capture the essence of the 'real I myself,' which is described as the power of thinking and reasoning. Therefore, while it is related to the theme of existence, it does not accurately define the 'real I myself' as presented in the text.

Option 2: "Our power of contemplation"

Explanation: Although this option touches on the concept of thinking, it is too vague and does not specifically address the 'real I myself.' The text emphasizes reasoning and judgment as key components of our true self, rather than just contemplation. Thus, this option fails to encapsulate the full meaning of the 'real I myself' as articulated in the passage.

Option 3: "Our flesh and bones"

Explanation: This option refers to the physical aspect of our being, which the text explicitly states cannot perceive things in nature. The 'real I myself' is described as existing apart from physical reality, focusing instead on thoughts and reasoning. Therefore, this option contradicts the main idea of the text regarding the nature of the 'real I myself'.

Option 4: "Our reasoning and judgment"

Explanation: This option accurately reflects the text's assertion that the 'real I myself' is embodied in our thoughts, reasoning, and judgment. The passage emphasizes that our true self is defined by our ability to think and make rational conclusions, which aligns perfectly with this option. It captures the essence of the 'real I myself' as the power that processes impressions and provides reasoning.