What is the definition of a duty of care in the context of personal injury cases?

The classic definition of duty has been in terms of foreseeability, but the definition itself is wide and general, and its application here becomes even more difficult because of the incursion of two other factors: the so-called 'unforeseeable' plaintiff and the infliction upon such plaintiff of emotional distress. As to the definition, one statement of it occurs in the famous case of Donoghue v. Stevenson (1932) A.C. 562, 580: 'The rule that you are to love your neighbour becomes in law, you must not injure your neighbour; and the lawyer's question, Who is my neighbour? receives a restricted reply. You must take reasonable care to avoid acts or omissions which you can reasonably foresee would be likely to injure your neighbour. Who, then, in law is my neighbour? The answer seems to be--persons who are so closely and directly affected by my act that I ought reasonably to have them in contemplation as being so affected when I am directing my mind to the acts or omissions which are called in question.'