"Thus the sum of things is ever being reviewed, and mortals dependent one upon another. Some nations increase, others diminish, and in a short space the generations of living creatures are changed and like runners pass on the torch of life"

The quote from Lucretius discuss the short-term and interconnected nature of presence. It assesses the perpetual cycle of modification and continuity on the planet, emphasizing both the change and connection of life. At its core, the passage recommends that presence is a dynamic procedure, eternally in flux. This might be interpreted as a reflection on the ancient philosophical idea of "panta rhei", or "whatever flows", which suggests that change is the basic nature of deep space.

The expression "the amount of things is ever being examined" indicates a cosmos in constant evaluation and adjustment, where the totality of presence-- including nature, societies, and individuals-- remains in a state of continuous reassessment and transformation. This lines up with the concept that nothing is fixed and that reality is always moving.

The mention of "mortals dependent one upon another" highlights the interconnectedness of human relationships and societies. It suggests that people, like all living things, depend on one another for survival, growth, and progress. This interconnectedness extends beyond individuals to incorporate countries and societies, which are likewise subject to the exact same concepts of rise and fall.

When Lucretius notes that "some countries increase, others decrease", he alludes to the political and social modifications that define human history. Civilizations rise to power, end up being dominant, and eventually decrease, just to be changed by others. This cyclical pattern mirrors the ebb and flow of human existence on a grand scale.

The concluding metaphor, "like runners pass on the torch of life", perfectly encapsulates the idea of life as a relay race. Each generation gets life from its predecessors, carries it for a while, and then passes it on to the next. This imagery signifies the continuity of life and its long-lasting presence despite the ceaseless modification. It also underscores a sense of duty and obligation in guaranteeing the perpetuation of life and understanding throughout generations.

In essence, Lucretius' reflection eloquently catches a viewpoint that acknowledges change as inevitable and elaborately woven with connection, highlighting the shared journey of all living things in the ever-unfolding tapestry of life.