Álvaro Santana-Acuña Published online: 10 April 2015 # Springer Science+Business Media New York 2015 Abstract Despite their groundbreaking explanations of social phenomena, Adam Smith’ s The Theory of Moral Sentiments (1759) and Gabriel Tarde’ s Monadology and Sociology (1893) still occupy a peripheral position in the sociological tradition. This article analyzes Smith’ s and Tarde’ s efforts to present sentiments and monads as foundations of social phenomena. Unlike contemporary contributions, more concerned with structuralist accounts of the social, the singularity of their works was to frame sentiments and monads as tangible units of analysis that permitted to find the source of individual action outside the self. Smith and Tarde argued so not by linking social causality to abstract and collective structures but rather to human interdependence and interaction. Along with contributing to a less teleological approach to the sociological tradition, this article argues that engaging with works outside the structuralist tradition provides researchers with a much-needed space for sociological innovation to explain social phenomena in an increasingly globalized and hyper-connected world. Keywords Society . Sentiments . Adam Smith . Monads . Gabriel Tarde Introduction Can works dealing with the exchange of sentiments and the interaction of monads improve our understanding of social phenomena in an increasingly hyper-connected and globalized world? (Bauman 2000; Castells 2010; Christakis and Fowler 2009; Padgett and Powell 2012; Sassen 2014) This article asks that question in order to contribute to previous Am Soc (2015) 46:194–218 DOI 10.1007/s12108-015-9264-y Álvaro Santana-Acuña is interested in the intersection between processes of valuation and material culture. He is currently finishing a book on the process by which some literary works attain classic value. Earlier drafts of this article benefited from comments by participants in the Symposium BRe-Envisioning the History of Sociology: Recognizing Social Theorists, Reconceptualizing the Social World^ (ASA, New York City, 2013), the Conference BThe Philosophy of Adam Smith (250th Anniversary of The Theory of Moral Sentiments)^ (Oxford University, 2009), and the Culture and Social Analysis Workshop at the Department of Sociology at Harvard University. I also thank Lorraine Daston, Michèle Lamont, Emma Rothschild, and AS reviewers for their suggestions. Á. Santana-Acuña (*) Department of Sociology, Harvard University, 33 Kirkland Street, Cambridge, MA 02138, USA e-mail: asantana@fas.harvard.edu Outside Structures: Smithian Sentiments and Tardian Monads