Peter Harman has published chiefly on the history of natural philosophy and physics in the 18th and 19th centuries, the period from Newton to Maxwell. Metaphysics and Natural Philosophy (1982) is a study of the philosophical foundations of physics in this period, focusing on problems of matter, force and energy. After Newton: Essays on Natural Philosophy (1993) collects essays on Newtonian natural philosophy and on Leibniz, Kant and Helmholtz. Energy, Force, and Matter: The Conceptual Development of Nineteenth-Century Physics (1982), published in hardback and paperback, and which has been translated into Italian, Spanish, Greek, Japanese, Chinese and Korean editions, provides an introduction to its subject.

His major research endeavour has been on James Clerk Maxwell, the major physicist of the 19th century, whose seminal contributions - field theory and statistical physics - rank in importance with the work of Newton and Einstein, and whose writings have been widely influential. Research for his edition of The Scientific Letters and Papers of James Clerk Maxwell was supported by the Royal Society, the Leverhulme Trust, the National Science Foundation and the Arts and Humanities Research Board. The edition, published in three volumes by Cambridge University Press (1990-2002) and reissued in digital paperback in 2008, encompasses Maxwell's extant correspondence and manuscript papers. The Natural Philosophy of James Clerk Maxwell (1998; reprinted in paperback 2001), based on his lectures as Zeeman Professor of the History of Physics at the University of Amsterdam in 1995, provides a comprehensive introduction to Maxwell's science and worldview.

His most recent work is a study of the aesthetics of nature in the period spanned by Newtonian science and natural theology, Charles Darwin’s Origin of Species (1859) and John Ruskin’s Modern Painters (1843-60). The Culture of Nature in Britain 1680-1860 (published by Yale University Press in 2009) embraces themes in art, literature, philosophy and science, exploring the interaction and cultural context of conceptions of ‘nature’ in terms shaped by the linked themes of design, exploration, landscape, flora and fauna, colour and vital forces - across conventional disciplinary and chronological boundaries, and within common terms of debate.

PUBLICATIONS

• The Culture of Nature in Britain 1680-1860 (New Haven and London: Yale University Press, 2009)
• Cambridge Scientific Minds, edited with Simon Mitton (Cambridge: Cambridge University Press. 2002; paperback 2002)
• The Scientific Letters and Papers of James Clerk Maxwell, vol. 3 (Cambridge: Cambridge University Press, 2002; paperback 2008)
• The Investigation of Difficult Things: Essays on Newton and the History of the Exact Sciences in Honour of D.T. Whiteside, edited with Alan E. Shapiro (Cambridge: Cambridge University Press, 1992; paperback 2002)
• The Natural Philosophy of James Clerk Maxwell (Cambridge: Cambridge University Press, 1998; paperback 2001) 
• The Scientific Letters and Papers of James Clerk Maxwell, vol. 2 (Cambridge: Cambridge University Press, 1995; paperback 2008) 
• After Newton: Essays on Natural Philosophy (Aldershot: Variorum, 1993) 
• The Scientific Letters and Papers of James Clerk Maxwell, vol. 1 (Cambridge: Cambridge University Press, 1990; paperback 2008)
• Wranglers and Physicists: Studies on Cambridge Physics in the Nineteenth Century, edited (Manchester: Manchester University Press, 1985)  
• The Scientific Revolution (London: Methuen, 1983; reprinted Abingdon and New York: Routledge, 2009) 
• Energy, Force, and Matter: the Conceptual Development of Nineteenth-Century Physics (Cambridge: Cambridge University Press, 1982; paperback 1982) 
• Metaphysics and Natural Philosophy (Brighton: Harvester Press, 1982)