It was at this point that Cavour intervened, sending the army of Piedmont southward (avoiding Rome which had a French Garrison, any attack would certainly provoke intervention) meet with Garibaldi, and stop him at any cost. Cavour's suspicion of Garibaldi is a much-talked about issue. He had no direct control over Garibaldi once Garibaldi had stopped being a General, and he though of Garibaldi as a radical revolutionary Mazzinian who would take unification at any cost. Additionally, the idea of Garibaldi being the shaper of a new Italy instead of Cavour was too much for him to take. Luckily Garibaldi recognised his own loyalty to Victor Emmanuel and Piedmont; and Italy, with the exception of Rome and Venetia, was now united. Both Cavour and Garibaldi put a great deal of effort into the unification process - Cavour in mostly diplomatic means and Garibaldi in mostly military.
When comparing the roles of Cavour and Garibaldi in Italian unification, it is necessary to take a look at the two parties' eagerness for the cause. Cavour did not originally favour unification. He was more interested in the self-aggrandisement of Piedmont. When he met with Napoleon III at Plombieres, all he wanted was for Piedmont to annexe Lombardy and Venetia and rid the new state of the Austrian influence. Essentially, Cavour was a conservative and an opponent of Mazzinian views. He was also a liberal in many respects and a socialist opposer. He was anti-clerical, and his main political policy was entitled 'Le juste milieu', a 'happy mean' between revolution and reaction. He was a brilliant businessman and a great moderniser within Piedmont. His main objective was to drive the Austrians out of the Italian states. He thought that once this had been achieved, if Piedmont could control Lombardy and Venetia, then it could dominate the rest of Italy without having to take it over.
Garibaldi on the other hand insisted that unification of Italy was essential. He even, to a certain extent, encouraged Cavour to help unify the whole of Italy. Giuseppe Mazzini was the man who influenced Garibaldi in taking up the cause for Italian unification. The two revolutionists had met years prior to the 1848 revolution and Mazzini instilled in Garibaldi a desire for unification at any cost. This was one of the things which Cavour was extremely suspicious about, and a large factor in the decision for Cavour's interception of Garibaldi's Thousand. It is important to remember that Cavour had recently lost control over Garibaldi, when Garibaldi had stopped being a General. Cavour's suspicion certainly destroys the myth surrounding the Risorgimento of the two working together to fight for a cause. It is certainly true that the cause was there for both, but the ways they approached it and the way it came about was fall less well planned than the 'beautiful legend'. Garibaldi's devotion to Victor Emmanuel and his recognition of the king as the sole ruler of the new Italy meant that any conflict between Cavour and Garibaldi did not amount to much.
Regarding the actual methods, Cavour used a rather diplomatic means in keeping with his 'Juste milieu'. This and the provocation of Austria into war allowed French involvement to strengthen Piedmont. However, Garibaldi used more militant means. As a Mazzinian, he was a strong believer in using revolutionary tactics such as popular uprisings, but since there had been so many unsuccessful attempts at this during the first half of the century, Garibaldi was now much more thorough in his preparation for taking over the southern states of Italy. Cavour understood that war was essential to drive away Austrian influence in Italy, but he wanted to use intelligent diplomacy in order to isolate Austria and receive help from France. Garibaldi, with help from his guerrilla training in South America, used and manipulated naval forces to fight against the state rulers in Naples and Sicily. He was not as careful in his planning as Cavour, and relied mainly on his military instinct, whereas Cavour, being highly intellectual, used his talent as a persuasive natural political leader to great effect.
Cavour and Garibaldi were also very different regarding the attitude towards foreign intervention in unifying Italy. Cavour advocated that Piedmont needed foreign help in trying to unify Italy especially after the Mazzinian failures of the 1820s and 1830s. For this reason, Cavour joined the Crimean War in 1854 on the side of Britain and France in order to gain favour from Napoleon III. It was close to this time that the meeting between Napoleon III and Cavour was arranged in Plombieres. Although Napoleon III betrayed him in the treaty of Villafranca, Cavour still sought help from him when Parma, Modena and Tuscany demanded Piedmontese rule (a plebiscite was eventually carried out). In contrast, Garibaldi believed in the Mazzinian ideal of Italy making itself (Italia fara da se). Additionally, he had great disdain for Cavour after Savoy and, more importantly, Nice (Garibaldi's birthplace) was given to France. However, it was clear that French intervention was necessary and the idea of Italy being 'fertilised by the blood of martyrs' was no longer relevant.
Cavour and Garibaldi also had different ideas regarding the form of government that would rule Italy once it had been created. Cavour favoured the rule of King Victor Emmanuel II (because of Cavour's monarchist leanings and the fact that he knew how to manipulate Victor Emmanuel for his own benefit), but Garibaldi suggested a Republican state. However, his loyalty to Victor Emmanuel made the idea impossible.
Garibaldi's thought a Republic was the only form of government that could bring about a strong country in which all the people are satisfied. Cavour though thought a Republic was a radical form of government. He was afraid of Garibaldi turning southern Italy into a Republic, which could compete with Piedmont, and this was another reason he intervened when he did.
One of Cavour's most important contributions to unification were the economic reforms he made (e.g. building up of industries, factories, railway lines etc.) which helped to make Piedmont stronger than ever before. Garibaldi did nothing of the sort, and therefore when assessing the contributions of the two, it is important to remember that without Garibaldi's military successes, he had nothing.
Both Cavour and Garibaldi were essential in helping to unify Italy. They were not the only two figures however. Mazzini stood as the 'Godfather' to all the Mazzinian tactics that many revolutionists used, and the writings of Balbo and Gioberti inspired many. It can be said that without one of them, unification would have been far less likely, but a combination of unlikely circumstances meant that, by accident, unification seemed to suddenly be within touching distance of Italy. It just finally required Cavour and Garibaldi to reach out and grab it.