Success means a business achieving its objectives — typically survival and profit for a new firm, and growth or market share as it matures. Enterprise — the entrepreneur's skill in organising the other factors and bearing risk — has a powerful claim to be the decisive factor.
The case that success depends mainly on enterprise. Enterprise makes every other factor productive: it decides what to produce, how to combine resources, and whether to take a given risk. Good entrepreneurial judgement — spotting a market gap, controlling cash, motivating staff, adapting to a dynamic environment — repeatedly explains why one firm thrives while a rival with similar resources fails. Because the business environment is constantly changing, the ability to make good decisions under uncertainty (a quality of enterprise) is arguably more important than any fixed stock of land, labour or capital.
The case against — the other factors are decisive too. Even excellent enterprise cannot succeed without the other factors of adequate quality: skilled, motivated labour to deliver consistent quality; sufficient capital (finance and modern equipment) to produce efficiently and at scale; and a suitable location (land) for access to customers or materials. Many well-led start-ups fail not through poor decisions but through lack of finance or a shortage of skilled workers. Moreover, much success is shaped by external factors outside all four — the state of the economy, competitor behaviour, or changes in the law — which even outstanding enterprise can only respond to, not control.
Weighing it up (criterion). The honest answer is that the factors are complementary, not substitutes, so success rarely depends on one alone. The relative importance of enterprise depends on the stage and type of business: at start-up, enterprise is usually the binding constraint, because nothing happens until the entrepreneur organises resources and takes the risk; for a capital-intensive firm (e.g. manufacturing), the quality and quantity of capital may matter as much as enterprise; for a service or knowledge business, the quality of labour can be decisive.
Judgement. On balance, the quality of enterprise is the most important single factor at the start of a business and in a fast-changing environment, because it determines how well all the other factors are chosen, combined and adapted. But it is not sufficient on its own: success depends on enterprise together with sufficient quality of the other factors and a favourable response to external conditions. The most defensible conclusion is that enterprise is the leading factor that unlocks the value of the others, rather than the sole cause of success — so success depends on enterprise to a large but not total extent, and most of all at start-up.