Answer: "Speculation on his own sanity" generally refers to the act of questioning or doubting one's own mental health or stability. This can be a form of self-reflection or introspection, but it can also be a symptom of a mental health condition such as anxiety, depression, or bipolar disorder.
The phrase "speculation on his own sanity" often suggests that a person is uncertain about their mental state, and may be experiencing a degree of confusion or distress as a result. This can be a difficult and unsettling experience, as it can be challenging to determine whether one's thoughts, feelings, and behaviors are within the normal range of human experience or are indicative of a mental health issue.
Overall, "speculation on his own sanity" is a complex and multifaceted concept that requires careful consideration and sensitivity to the individual's unique circumstances and experiences.
Explanation: The phrase "speculation on his own sanity" in this context refers to the Japanese foreign minister Matsuoka's statements about his own mental health during a meeting with Ambassador Grew. The text suggests that Matsuoka made insulting and rambling remarks, including comments about his own mental state, during the meeting. The implication is that Matsuoka's behavior was erratic or unstable, which may have been intended to intimidate or confuse the American ambassador.
The phrase may also suggest that Matsuoka was using his own mental state as a rhetorical device or bargaining chip in his negotiations with the United States and Germany. By suggesting that he was mentally unstable or unpredictable, Matsuoka may have been trying to gain an advantage in his diplomatic dealings. However, it is unclear from the passage whether Matsuoka's comments about his own sanity were genuine or simply part of a strategy to achieve his political goals.