In Victor Hugo's "Les Misérables," the distinction between the past and the future is depicted as a transition from ghostly figures to tangible forms. The phrase "the men of yesterday are spectres" suggests that the people of the past are no longer significant, having faded into memory. In contrast, the "men of tomorrow" represent the potential and evolving nature of humanity, indicating that the future is filled with possibilities yet to be realized.

Hugo emphasizes that while the spiritual eye can perceive these changes, the vision remains unclear. This highlights the philosophical aspect of the future, which is rooted in imagination and ideals. The embryonic nature of future developments reflects the growth and transformation of society, shaped by philosophy and human experience. Thus, the text invites contemplation on the nature of progress and the role of philosophy in guiding humanity toward a better future.