The turn to systems thinking in agriculture has been decisive. It is now second-nature to speak of agroecosystems, and this powerful way of seeing and understanding agricultural activities reveals myriad possibilities for a more beneficent agriculture. But systems thinking is not without its dangers and limits. Its emphasis on connections can lead us to overlook, to perhaps take as anomalous, unconnected and ever-evolving aspects of the world. Thus systems thinkers must be vigilant to keep in mind that imagining phenomena as a system is a useful intellectual construct, rather than perfect vision. We have been working on two, perhaps more specific, aspects of systems thinking that trouble us: the question of where to draw boundaries, and how to think about sources of change and innovation in a systems portrayal. We propose that Koestler's holon is a useful device for envisioning the farm (be it individual, household, or corporation) and thus many agroecological questions. The holon is simultaneously a whole and a part of larger wholes. That it is in some ways a whole is manifested in its intentional planning and acting so as to persist and thereby continue to provide livelihoods. But it is also a part of many larger wholes, the contexts in which it exists, e.g., biophysical and social. To persist it must find configurations that are simultaneously viable in these multiple contexts.  When contexts shift, as they inevitably will, the farm holon must reconfigure to remain viable. From this imperative to accommodate changing contexts comes innovation and change. The farm-as-holon perspective helps us see intentionality as what draws together the human, biological and inanimate parts of an agricultural endeavor. Further, constant planning and action is essential to maintaining this assemblage as a recognizable entity. Thus farm-as-holon suggests a compelling agroecological boundary and the source of ever-present change.