Final answer:
The existence of unyielding obstacles to our will serves as a counterargument to solipsism because it suggests an autonomous reality beyond one's psyche, indicating a world that is not subservient to the mind's desires or control.
Step-by-step explanation:
The existence of obstacles to our will can be considered a counterargument to solipsism because solipsism posits that only one's own mind is sure to exist. However, if the external world is merely a creation of our mind, then theoretically, it should align with our desires and will without resistance. The presence of forces out of our control, like the laws of nature that dictate our physical limitations, suggests the existence of a reality that operates independently of our conscious mind. This goes against solipsistic notions, as it implies a world beyond just one's mental states, where free will is not absolute.
Obstacles such as the unpredictability of other people's behavior or the constraints imposed by physical laws are not in harmony with the individual's will, pointing to an external reality that cannot be altered by mere thought. Thus, these obstacles contradict solipsism by highlighting the existence of an external world that resists the notion that the mind alone constitutes reality.