I can't do better than to recommend that you consult the SEP entry on monism written by Jonathan Schaffer. It's not clear to me from your question whether you favor what Schaffer calls "existence monism" or instead what he calls "priority monism," but you'll find both views expertly discussed.
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I am wondering if there is an alternative between nominalism and realism. Both of these theories agree that particulars exist but they disagree about the relationship between the particulars and their properties. However, what if there are no individual particular entities that are independent with their own self-nature? In our modern times, we often discuss how entities are interconnected and, to some extent, dependent on other entities. In the field of Social Work, for example, the micro, mezzo, and macro environments affect each other and the line between the three are constantly blurred and uncertain. Believing in a "mechanical" world that is made up of separate individual parts is becoming increasingly difficult to believe.